Fibreflex Operating Manual

Chapter 0LFXG-H Detector with GEN2000® Electronics

Installation and Operation Guide

For HART® applications measuring continuous level

Manual part number 31386-USCD part number 32700

Version 1.1

LFXG-H Installation and Operation Guide

Revision History

Copyright© 2006 Ohmart/VEGA Corporation, Cincinnati, Ohio. All rights reserved.

This document contains proprietary information of Ohmart/VEGA Corporation. It shall not be reproduced in whole or in part, in any form, without the expressed written permission of Ohmart/VEGA Corporation.

The material in this document is provided for informational purposes and is subject to change without notice.

GEN2000® is a registered trademark of the Ohmart/VEGA Corp. Ohmart/VEGA View and Ohmview 2000 are trademarks of Ohmart/VEGA Corp.

HART® is a registered trademark of The HART® Communication Foundation.

ISO 9001 approval by Lloyd's Register Quality Assurance Limited, to the following Quality Management System Standards: ISO 9001:1994, ANSI/ASQC Q9001-1994, Approval Certificate No. 107563.

Ohmart/VEGA Corporation4241 Allendorf DriveCincinnati, Ohio 45209-1599 USA

Tel: +1 513-272-0131

Fax: +1 513-272-0133

Website: www.ohmartvega.com

Field service E-mail: [email protected]

Manual number 31386-US CD 32700

November 2006

Version 1.1

Version Description Date1.0 Initial release. Formerly

245634-EN051201

1.1 Changed CD part number 32700

061127

Warning: To ensure CE compliance, use this equipment only in the manner that this manual describes, per Ohmart/VEGA specifications. Otherwise, damage to the unit or personal injury may result.

Revision History. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i-2Explanation of symbols. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i-viiYour comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i-ixChapter 1: Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1Nuclear materials notice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1Unpacking the equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2Storing the equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

Source holder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3Gauge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

LFXG-H specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4Typical applications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6Principle of operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7System overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8

Source holder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8Detector assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9

Communicating with the gauge . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-10Using a field communicator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10Using Ohmview 2000 Software on a PC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11

Customer Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-13U.S. and Canada. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13Worldwide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13Have this information ready . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13

Chapter 2: Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1Testing on the bench . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1Location considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

Stable temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3Protect insulation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3Avoid internal obstructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3Avoid external obstructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4Avoid source cross-talk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4

Mounting the measuring assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5Wiring the equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7Switch for CE compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8Output current loop. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8

Relay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8RS-485 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8

Communication. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9Process alarm override switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9Conduit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9

Commissioning the gauge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-10Field service commissioning call checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10

Chapter 3: Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

Table of Contents

Calibrating the current loop (analog output). . . . . . . . . . . . . . . . . . . . . . . 3-2Measuring the current loop output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

Calibration methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4Theory of calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4

Both calibration methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4Standard calibration method. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5Simple calibration method. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7

Choosing the linearizer type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8Table - Non-linear. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8Table - Linear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9

Checking the gauge repeatability. . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10Calibration procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11

1 Setting the low level and collecting Cal Low data . . . . . . . . . . . . . . . . . . . . . . 3-122 Setting the high level and collecting Cal High data . . . . . . . . . . . . . . . . . . . . . 3-133 Collecting the linearizer table data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-134 Calculating the linearity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-155 Calculating the calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-15Repeating the calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-16

Periodic process standardization. . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-17Standardization reminder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-17

Chapter 4: Advanced functions. . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1Process chain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2Gauge Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

Process Variables tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4Gauge Info tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5Min/Max History tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6

New hardware or corrupt EEPROM. . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7New Hardware tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7Responding to the New hardware found message . . . . . . . . . . . . . . . . . . . . . . . . . 4-8

When new hardware is installed. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8When new hardware is not installed. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8

Test modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9Current Loop Test (milliamp output) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10Sensor Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-11Auxiliary Input Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12Relay Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12Temperature Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-13

Selecting the transmitter’s type and location . . . . . . . . . . . . . . . . . . . . . 4-14Gauge Setup tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15

Chapter 5: Diagnostics and repair . . . . . . . . . . . . . . . . . . . . . . . . 5-1Software diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

Gauge Status tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2Diagnostic alarms and HART messages . . . . . . . . . . . . . . . . . . . . . . . . . 5-3

Relay Setup tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3Gauge status diagnostics screens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3Acknowledging diagnostic alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4

Diagnostic alarm messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4Analog alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7Process alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7X-ray alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7Auxiliary x-ray alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8

History information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9Diag History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9

Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10Circuit board identifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10Test points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-11Jumpers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12LED indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12

CPU board LED indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12Maintenance and repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15

Periodic maintenance schedule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15Source Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15

Recording the source wipe and shutter check . . . . . . . . . . . . . . . . . . . . . . . . . . 5-16Field repair procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-17

Spare parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-17Replacing the CPU or Power supply board. . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-18Requesting field service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-20Returning equipment for repair to Ohmart/VEGA . . . . . . . . . . . . . . . . . . . . . . . . 5-21

LFXG-H Installation and Operation Guide v

0.1 Explanation of symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-31.1 LFXG-H specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-41.2 Contact information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-103.1 Calibration methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-43.2 Standard calibration sensor counts and levels record . . . . . . . . . . . . . . . . .3-104.1 Process Chain tab — display values. . . . . . . . . . . . . . . . . . . . . . . . . . 4-24.2 Process Variables tab — display values . . . . . . . . . . . . . . . . . . . . . . . . 4-34.3 Gauge Info tab — additional display values . . . . . . . . . . . . . . . . . . . . . . 4-44.4 Min/Max History tab — display values . . . . . . . . . . . . . . . . . . . . . . . . . 4-55.1 Alarm types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15.2 Alarm type outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-25.3 Diagnostic alarm conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-45.4 Power supply board test point labels . . . . . . . . . . . . . . . . . . . . . . . . .5-105.5 CPU test point labels. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-105.6 Jumper settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-115.7 Power supply board LED summary . . . . . . . . . . . . . . . . . . . . . . . . . .5-125.8 CPU board LED summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-135.9 Periodic maintenance schedule . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-145.10 Spare parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-15

Tables

vi LFXG-H Installation and Operation Guide

LFXG-H Installation and Operation Guide vii

Chapter 0PREFACE

Explanation of symbolsIn the manual

Radiation noticeIntroduces information concerning radioactive materials or radiation safety.

CautionIntroduces warnings concerning potential damage to the equipment or bodily harm.

On the instrumentAC current or voltageA terminal to which or from which an alternating (sine wave) current or voltage may be applied or supplied.

DC current or voltageA terminal to which or from which a direct current voltage may be applied or supplied.Potentially hazardous voltagesA terminal on which potentially hazardous voltage exists.

Protective ground terminalIdentifies location of terminal intended for connection to an external conductor.

viii LFXG-H Installation and Operation Guide

Your commentsManual: LFXG-H Installation and Operation Guide

Date: ______________

Customer Order Number: ___________________

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Did you find errors in this manual? If so, specify the error and page number.

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__________________________________________________________________________________________________________________________________________

LFXG-H Installation and Operation Guide 1-1

C H A P T E R

1Chapter 1INTRODUCTION

Nuclear materials noticeThis equipment contains radioactive source material that emits gamma radiation. Gamma radiation is a form of high-energy electromagnetic radiation. In many cases, only persons with a specific license from the U.S. NRC or other nuclear regulatory body may perform the following to the source holder:

• Dismantle

• Install

• Maintain

• Relocate

• Repair

• Test

Ohmart/VEGA Field Service engineers have the specific license to install and commission nuclear gauges, and can instruct you to safely operate your level gauge. See page 1-11 for contact information.

Note: See the Radiation Safety for U.S. General and Specific Licensees, Canadian and International Users Manual and the Radiation Safety Manual Addendum of Reference Information CD that came with the source holder and the appropriate current regulations for details.

1-2 LFXG-H Installation and Operation Guide

Introduction

Unpacking the equipment

Unpack the unit in a clean, dry area.

Inspect the shipment for completeness. Check against the packing slip.

Inspect the shipment for damage during shipment or storage.

If the detector is included as a separate package in the shipment, inspect the assembly for damage that may have occurred during shipment or storage.

If there was damage to the unit during shipment, file a claim against the carrier, reporting the damage in detail. Any claim on the Ohmart/VEGA for shortages, errors in shipment, etc., must be made within 30 days of receipt of the shipment.

If you must return the equipment, see the section Returning equipment for repair to Ohmart/VEGA in the Diagnostics and repair chapter.

After unpacking the equipment, inspect each source holder in the shipment to ensure that the operating handle is in the OFF position. If you find the handle in the ON position, place it in the OFF position immediately and secure it. Note: This applies to only some source holders.

Caution: You must be familiar with radiation safety practices in accordance with your U.S. Agreement State, U.S. NRC, or other nuclear regulatory body before unpacking the equipment.

Note: Most source holder models accept a lock. Call Ohmart/VEGA Field Service (see Customer Service on page 1-11 for contact information) immediately for further instructions if:

l The source holder does accept a lock and there is no lock on it.l The lock is not secured.l You cannot secure the lock.l The operating handle does not properly move into the OFF position.

See the Radiation Safety for U.S. General and Specific Licensees, Canadian and International Users Manual and the Radiation Safety Manual Addendum of Reference Information that came with the source holder and the appropriate current regulations for details.


Introduction

Storing the equipment

Source holderIf you must store it, do so in a clean, dry area. Be sure its shutter is in the OFF or CLOSED position (if applicable). Check the current local regulations (U.S. NRC, Agreement State, or other) to determine whether this area must have any restrictions.

GaugeAvoid storage at temperatures below freezing. Store the gauge indoors in an area that has temperature control between +10 °C to +35 °C (+50 °F to +95 °F) and < 50% relative humidity. Store equipment in dry conditions until installation.

LFXG-H specificationsTable 1.1 LFXG-H specificationsSystem Accuracy ±1% of span

typicalAccuracy depends on specific application parameters

Active Lengths Flexible detector 305 – 7,010 mm (12 – 276") in 305 mm (12") increments

Typical Sources Cesium-137 0.66 MeV gamma radiation emitter, 30.2 year half life

Cobalt-60 1.2 and 1.3 MeV gamma radiation emitter, 5.3 year half life

Power Requirements*

AC 100 – 230 ±10% VAC (90 – 250 VAC, or with internal heater kit: 115 – 230 VAC) at 50 – 60 Hz, at 15 VA maximum power consumption (25 VA ≤ with heater) CE compliance requires 100 – 230 ±10% VAC

DC 20 – 60 VDC (< 100 mV, 1 – 1,000 Hz ripple) at 15 VACE compliance requires 24 VDC ± 10%

Wiring Per local codeSignal Cable Maximum length 1,000 m (3,280')

HART signal 1.02 – 0.643 mm (no. 18 or 20 AWG) 2-conductor shielded


Introduction

GEN2000® Electronics Housing

4-wire hookup with DC

1.02 – 0.643 mm (no. 18 or 20 AWG) 4-conductor shielded

Certification to CSA and UL standards

• Designed to meet National Electric Code (U.S. and Canada)

• Class l, Groups A, B, C and D, Div 1 and 2 • Class ll, Groups E, F and G, Div 1 and 2

ATEX Certification II2 G/D EEx d IIC T6 IP66 -20 °C to +60 °CII2 G EEx d IIB+H2 T6 -50 °C to +60 °C

Enclosure rating NEMA 4X IP-66Ambient temperature

-20 °C to 50 °C (-4 °F to 122 °F) option for lower temperatures available

Humidity 0 – 95%, non-condensingVibration Tested to IEC 68-2-6, IEC 68-2-27, and IEC 68-2-36Material Cast aluminum ASTM A 357Paint Epoxy Powder Coat

Table 1.1 LFXG-H specifications (continued)


Introduction

Typical applicationsOhmart/VEGA’s level gauges accurately indicate the level of liquids or bulk materials in vessels, reactors, or tanks.

In order to achieve a level indication over the desired length, it may be necessary to use more than one detector. The way these multiple detectors link together depends upon the types of detectors used. Specific details on using multiple detectors are available from Ohmart/Vega Corp.

The accuracy of quality control systems that use Ohmart/VEGA nuclear level gauges is profitable to a wide range of industry operations. A number of applications that use a level gauge are:

Pulp and Paper

• Liquors

• Bleach plant chemicals

• Coating chemical storage

• Lime mud

Weight Housing detector 0.0015 x Length (mm) + 5.44 kg (0.084 x Length (inches) +12 lb)

Current Loop Output Rating 4 – 20 mA, isolated, into 250 – 800 Ω Power Jumper selectable: source (active) or sink (passive)

modeRelay Output Software

user-settleableDiagnostic alarm or process high/low alarm function

Rating 6 A at 240 VAC, or 6 A 24 VDC (SPDT Form C), or 1/4 HP at 120 VAC

HART® Communication

HART Protocol BEL202 FSK standard current loop outputPC interface HART modem and Ohmart/VEGA communications

softwareOptional hand-held interface

Emerson Field Communicator model 375 with Ohmart/VEGA device descriptions loaded

Auxiliary Input Capability

Type Frequency input (0 – 100 kHz)Possible function Optional NORM or vapor phase compensation,

multiple gauge linking, and othersElectronics On-board memory FLASH and 2 EEPROMs

Real-time clock Maintains time, date, source decay compensation, and is Y2K compatible

Diagnostics LED indication +6V, Memory Corruption, HART, CPU Active, Auxiliary, High Voltage, Relay and Field Strength

Table 1.1 LFXG-H specifications (continued)


Introduction

• Wastewater treatment tanks

Chemical

• Low pressure/low vapor chemical storage

• Settlers

• Surge tanks

Food and beverage

• Food slurries

• Pastes

• Syrups

• Dough level

• Intermediate batch storage

Water and wastewater

• Settling/aeration tanks

• Clarifiers

• Sludge holding tanks

• Wet wells

Principle of operationThe gauge receives a shaped or collimated beam of radiation from the source holder through the process material. The material in the vessel shields part of the detector from exposure to the radiation field. As the process material level decreases, the detector senses more radiation, and vice versa.

Calibrating the gauge associates the detector readings (or counts) with the level of the material in engineering units. The output range of the gauge is a 4 – 20 mA current loop signal, in proportion to the level of the process.

System overviewThe gauge uses Ohmart/VEGA’s GEN2000®, Ohmart/VEGA’s newest compact electronics that support 4 mA – 20 mA HART® protocol, frequency, or field bus output. The level measurement system includes:

• Source holder

• FiberFlex flexible detector assembly


Introduction

• Communication device (HART modem with PC and Ohmart/VEGA software or Emerson Field Communicator 375)

Source holder• A cast or welded steel device that houses a radiation-emitting source capsule

• Directs the radiation in a narrow collimated beam through the process vessel

• Shields the radiation elsewhere

• The model chosen for each system depends on the source capsule inside and the radiation specifications

• Its shutter completely shields the radiation (source off) or lets it pass through the process (source on) (if applicable)

6

PC

System Overview


Introduction

Detector assembly• Mounts opposite the source holder.

• Inside the flexible detector is a scintillator material, which produces light in proportion to the intensity of its exposure to radiation.

• A photomultiplier tube detects the scintillator's light and converts it into voltage pulses.

• The microprocessor receives these voltage pulses after amplification and conditioning by the photomultiplier tube.

• The microprocessor and associated electronics convert the pulses into an output that can be calibrated.

Power supply board

CPU board

RS-485 ground (if applicable)Internal housing

ground

External housingground

GEN2000 exploded view


Introduction

Communicating with the gaugeThe gauge is a transmitter that produces the current loop signal directly at the measurement site.

Use a field communicator or HART modem and Ohmview 2000 software with a PC to enable:

• Initial setup

• Calibration

• Other communication with the gauge

You can make a connection anywhere along the 4 mA – 20 mA current-loop line. After setup and calibration of the gauge, there are no everyday requirements for external electronics.

Using a field communicatorOhmart/VEGA’s gauge is compatible with the Emerson 375 Field Communicator or equivalent.

To function, the minimum load resistance on the 4 mA – 20 mA loop must be 250 Ω. See the instruction manual for your field communicator for information about:

• Key usage

• Data entry

• Equipment interface

To effectively use the gauge features, you must use Ohmart/VEGA's device description (DD) to program the HART communicator. You can purchase a field communicator, programmed with the DD, through Ohmart/VEGA (Ohmart/VEGA part number 244880).

Use firmware 2000.00 or higher when you use the field communicator to use NORM or vapor compensation.

Note: There are some minor differences in operation of the Ohmview 2000 software and the field communicator. Most significantly, Ohmview 2000 software writes entries immediately to the transmitter, but a field communicator must be manually told to sends changes.


Introduction

Using Ohmview 2000 Software on a PCWhen you use a PC with Windows and a Pentium processor to communicate with the gauge or other Ohmart/VEGA HART transmitter field devices, you must have a HART modem and the Ohmview 2000 software kit (part number 243008), which includes:

• Modem

• Cables

• Software

Ohmview 2000, RS-485 Network, Ohmview 2000 Logger, and Ohmview 2000 Configurator software are Windows programs that emulate the Field Communicator Model 375. Ohmview 2000:

• Charts the 4 mA – 20 mA current output graphically

• Stores and retrieves configuration data to disk

• Enables offline editing of configurations

The Ohmview 2000 Software includes:

• Main Ohmview 2000 software

• HART Communication Server

• Launcher program

• Ohmview 2000 Logger

• Ohmview 2000 File Configurator

• Ohmview 2000 Electronic User Manual

Example of Ohmview 2000 Software


Introduction

When you insert the CD, the program installs these programs onto your hard drive.

Customer Service

U.S. and CanadaOn-site field service is available in many locations. Often, a field service engineer is at your plant for your gauge’s startup. Field service engineers also provide assistance by phone during office hours.

For emergencies (example: line shut down because of Ohmart/VEGA equipment), you can reach us 24 hours a day.

WorldwideContact your local Ohmart/VEGA representative for parts, service, and repairs.

Have this information readyOhmart/VEGA Customer Order (C.O.) Number

Located on the source holder’s engraved label

Gauge‘s serial number

Located on the gauge’s external housing

Note: The HART Communication Server must always be on when using Ohmview 2000's main program and Ohmview 2000 Logger.

Table 1.2 Contact informationTel (Monday – Friday 8:00 A.M. – 5:00 P.M. EST) +1 513-272-0131Tel (emergencies: follow the voice mail instructions) +1 513-272-0131Fax +1 513-272-0133Field service e-mail [email protected]


Introduction


C H A P T E R

2Chapter 2INSTALLATION

Testing on the benchTo ensure a quick start up after installation, you can test the detector assembly with the HART compatible communication device (a field communicator or a PC with a HART modem and Ohmart/VEGA software). Bench testing lets you check:

• Power

• Communication

• Initial setup software parameters

• Some diagnostics

Note: You may need to reset the time and date if the gauge has not had power for > 28 days. The Real Time Clock Fail message may appear. You must enter the correct time and date: the clock is the basis for source decay calculations.

GEN2000 terminals 13 and 14

250 – 800 Ω load resistor (optional)

Mini clips

HART modem

RS-232 cable

PC running Ohmart/VEGA software

Transmitter test points

H1H2

Bench test setup


Installation

You can calibrate the current loop output on the bench before mounting the detector on the process. See page 3-3.

Location considerationsWhen you ordered the gauge, Ohmart/VEGA sized the source for optimal performance. Notify Ohmart/VEGA before installing the gauge if its location differs. Satisfactory operation depends on proper location.

Stable temperatureMount the gauge on a portion of the line where the temperature of the process material is relatively stable. Process temperature can affect the gauge indication. The amount of the effect depends on:

• Sensitivity of the gauge

• Temperature coefficient of the process material

Protect insulationProtect from liquid any insulation between the measuring assembly and the process. The absorption of a liquid, such as water, can affect the gauge indication because it blocks some radiation.

Avoid internal obstructionsThe best possible installation of a nuclear level gauge is on a vessel that has no internal obstructions (example: agitator, baffle, man ways) directly in the path of the radiation beam. If one of these obstructions is present, it can shield the radiation from the detector, causing an erroneous reading.

If the vessel has a central agitator, the source holder and detector can mount to the vessel on an arc other than a diameter, so the beam of radiation does not cross the agitator. You can avoid other obstructions this way.

Note: Locate the source holder where process material cannot coat it. This ensures the continuing proper operation of the source ON/OFF mechanism (if applicable). Many regulatory bodies (example: the U.S. NRC) require periodic testing of the ON/OFF mechanism.

See the Radiation Safety for U.S. General and Specific Licensees, Canadian and International Users Manual and the Radiation Safety Manual Addendum of Reference Information that came with the source holder and the appropriate current regulations for details.


Installation

Avoid external obstructionsAny material in the path of the radiation can affect the measurement. Some materials that are present when the gauge initially calibrates pose no problem because the calibration accounts for their effect.

Examples:

• Tank walls

• Liners

• Insulation

However, when the materials change or you introduce new ones, the gauge reading can be erroneous.

Examples:

• Insulation that you add after calibration absorbs the radiation and causes the gauge to erroneously read upscale.

• Rapidly changing tank conditions due to material buildup. Regular standardizations compensate for slowly changing tank conditions due to material buildup. See the Calibration chapter for information on standardization.

Avoid source cross-talkWhen multiple adjacent pipes or vessels have nuclear gauges, you must consider the orientation of the source beams so each gauge senses radiation only from its appropriate source.

The best orientation, in this case, is for the source holders to be on the inside with radiation beams pointing away from each other.

Mounting the measuring assemblyMounting options:

• Bracket mount

The L-bracket supports the electronics housing. For this type of mounting, the conduit clamps should be spaced every 18" (45cm).

• Conduit mount


Installation

This type of mount consists of an adapter with a 2" conduit coupler (part number 240721). It provides an air hose fitting for applications that must cool the gauge. The pole mount requires a nipple and union.

Wiring the equipment

Note: The detector’s active area (where it is possible to make a level measurement) is between 1" (25mm) from the bottom of the GEN2000 housing to the end of the flexible conduit. Mount the detector so this area spans the measurement length.

Note: In some cases, the handle on the source holder operates a rotating shutter. When installing or removing the assembly from the pipe, you must turn the handle to the closed (OFF) position and lock the handle with the combination lock provided.

FiberFlex mounting

Note: If you received an interconnect drawing from Ohmart/VEGA or the engineering contractor and the instructions differ from the instructions in this manual, use the drawing. It may contain special instructions specific to your order.


Installation

Use the drawing notes and the steps that follow to make the input and output connections. Make the connections at the removable terminal strips mounted on the power board. To access the power board, remove the explosion-proof housing cap.

Ohmart/VEGA provides an internal and external ground screw to connect the power Earth ground wire. Remove the top cover; the internal ground screw is located at the front of the housing. The external ground screw is located next to the conduit entry.

Internal housingground

GEN2000 internal and external ground screw

External housing ground

CPU board

RS-485 ground (if applicable)

Power supply board

Mounting bracket


Installation

Power

The AC power source voltage input is 100 – 230 VAC ± 10% (90 – 250 VAC) at 50-60 Hz, at 15 W (or 25 W with optional heater) maximum power consumption.

AC power must not be shared with transient-producing loads. Use an individual AC lighting circuit. Supply a separate earth ground.

The DC power source voltage input is 20 – 60 VDC (< 100 mV, 1 – 1,000 Hz ripple) at 15 VA maximum power consumption. DC power cable can be part of a single cable 4-wire hookup, or can be separate from output signal cable. (See Output current loop section.)

Note: Not all connections are required for operation.

The power input terminals are not polarity-sensitive.

Relay:- normally open- common- normally closed

L1AC or DC power input

L2

RY NO

RY C

RY NC

Not used in HART applications

Auxiliary input power

Common

Auxiliary input frequency signal

Current loop output

Interconnecting terminals — GEN2000 with HART

Caution: Do not apply power until thoroughly checking all wiring.


Installation

Use wire for power per local code. Use supply wire suitable for +40 °C above surrounding ambient temperature. All field wiring must have insulation suitable for 250 volts or higher.

Switch for CE complianceFor CE compliance, install a power line switch ≤ 1 m from the operator’s control station.

Output current loopOutput signal is 4 – 20 mA into 250 – 800 Ω. Pin 13 is + and Pin 14 is -. HART communication protocol (BEL202 FSK standard) is available on these connections. The output is isolated to standard ISA 50.1 Type 4 Class U.

When using signal (current loop or 4 – 20 mA output) cables that Ohmart/VEGA did not supply, they must meet these specifications:

• Maximum cable length is 1,000 m (3,280')

• All wires should be per local code

When using DC power, the signal and power can run on a single cable 4-wire hookup (2 wires for power, 2 for 4 – 20 mA).

Relay Use relay contacts rated at 6 A at 240 VAC, 6 A at 24 VDC, or 1/4 HP at 120 VAC. Frequency input signal is 0 – 100 kHz ≤, true digital.

RS-485The maximum cable length is 609 meters (2,000'). Use shielded wire per local code.

Connect positive terminals together. Connect negative terminals together. Connect ground terminals together.

Note: HART signal may not operate with some isolating barriers or other non-resistive loads.


Installation

CommunicationThe HART hand-held terminal can connect anywhere across the 4 mA – 20 mA wires to communicate with the gauge. A minimum requirement is a 250 Ω load-resistance on the current loop. A HART modem may connect across the 4 – 20 mA wires to enable communication between the gauge and a PC.

Process alarm override switchIf the output relay is set as a process alarm relay (high- or low-level alarm), you can install an override switch to manually deactivate the alarm. If you do not, the process alarm relay de-energizes only when the measured level is out of the alarm condition.

ConduitConduit runs must be continuous and you must provide protection to prevent conduit moisture condensation from dripping into any housings or junction boxes. Use sealant in the conduit, or arrange the runs so they are below the entries to the housings and use weep holes where permitted.

You must use a conduit seal-off near the housing when located in a hazardous area. Distance must comply with local code.

If you use only one conduit hub, plug the other one to prevent dirt and moisture from entering.

RS-485 Interface

Cable for power per local codes

PowerEarth

ground

ATEX groundHousing ground

Relay

Auxiliary frequency input

Sensor locations Control room

System architecture

Optionalmodem

Output signal cable

Optional field communicator

Emerson 375

mA Input to

DCS

PC

Example GEN2000 level gauge wiring


Installation

Commissioning the gaugeDepending on the source holder’s type, the process of commissioning the gauge can include:

• Taking appropriate radiation field tests

• Checking the pre-programmed setup parameters

• Calibrating on process

• Verifying the working of the gauge

You must remove the source holder lock or shield the first time the gauge takes measurements in the field. Only persons with a specific license from the U.S. NRC, Agreement State, or other nuclear regulatory body may remove the source holder lock.

Field service commissioning call checklistIn many U.S. installations, an Ohmart/VEGA field service engineer commissions the gauge. To reduce service time and costs, use this checklist to ensure the gauge is ready for commission before the engineer arrives:

Mount the source holder and detector per the Ohmart/VEGA certified drawings.

Allow access for future maintenance.

Make all wiring connections per the certified drawings and the section Wiring the equipment on page 2-4. Tie in the wiring from the field transmitter analog output to the distributed control system (DCS)/programmable logic controller (PLC)/chart recorder.

Ensure that the AC power to the transmitter is a regulated transient-free power source. UPS type power is the best.

If using DC power, verify that the ripple is < 100 mV, 1 – 1,000 Hz at 15 W.

Note: Users outside the U.S. must comply with the appropriate nuclear regulatory body’s regulations in matters pertaining to licensing and handling the equipment.


Note: The equipment warranty is void if there is damage to the gauge due to incorrect wiring not checked by the Ohmart/VEGA field service engineer.


Installation

Have process ready for calibration.

When possible, it is best to have process available near the low and high end of the measurement span.

When possible, it is best to be able to completely fill and empty the vessel at the high and low levels for the initial calibration procedure, and at 10% increments in between for the linearization procedure.

Do not remove the lock or shield on the source holder. Notify Ohmart/VEGA Field Service if there is damage to the source holder.


C H A P T E R

3Chapter 3CALIBRATION

Before using the gauge to make measurements, you must:

• Calibrate it to relate the detection of radiation from the source to the level of the process material.

• Calibrate the current loop to a reference ammeter or the DCS.

• Periodically, you must standardize the system on process to adjust for changes over time.

Calibration establishes a reference point or points that relate the detector output to actual (or known) values of the process.

You must make a calibration on process before the gauge can make accurate measurements. Perform the calibration after the installation and commission of the gauge at the field site.

You do not need to repeat the calibration procedures if certain critical process and equipment conditions remain unchanged. The gauge requires only a periodic standardization to compensate for changing conditions.

Calibrating the current loop (analog output) Calibrating the current loop adjusts the 4 mA – 20 mA output to a reference, the PLC/DCS or a certified ammeter. It forces the 4 mA and 20 mA outputs to the external reference. The Ohmart/VEGA factory pre-adjusts the current loop with a certified ammeter, so it is very close to the outputs required.


Calibration

To correlate the 4 mA – 20 mA to the process value, set the span of the current loop output.

A direct measurement of the current is preferable: hook the meter up in series with the instrument and the DCS. However, if you know the resistance of the DCS, use a voltage measurement to calculate the current.

Measuring the current loop output

Before a current loop calibration:

Connect an ammeter or the DCS to:

• Terminal connections 13 (mA +) and 14 (mA -)

• Test points H1 and H2

• Anywhere along the current loop

Make sure there is a 250 – 800 Ω load on the current loop. If no load or an insufficient load exists on the loop, it may require temporary placement of a resistor across terminals 13 and 14. Hook the meter or DCS in series with the load resistor.

Note: The current loop and process spans are independent and set separately. The current loop span sets the level indications for the 4 mA and the 20 mA outputs. The process span sets the endpoints of the calibration curve.

Current meter Voltmeter

Terminal block pins 13 and 14

Detector housing

DCS RtRt

Terminal block pins 13 and 14

Detector housing


Calibration

Procedure 3.1: To calibrate the current loop

You can check the current loop output calibration at any time by using the test mode to output a user-specified milliamp setting. See page 4-10.

1. Select Calibration | Current Loop Cal.

2. Click Execute.

3. Click OK.

4. Read the ammeter; enter the actual milliamp reading.

5. Click OK.

6. Click YES if the ammeter reads 4.00 mA or NO for any other reading.

7. Repeat until the meter reads 4.00 mA. The meter approaches the 4.00 mA successively.

8. Read the ammeter; enter the actual milliamp reading.

9. Click OK.

10. Click OK.

Note: If using a voltmeter, calculate the current value.


Calibration

Calibration methodsFor each installation, you must choose a method to calibrate the gauge. In almost all cases, the standard method is the best.

Theory of calibration

Both calibration methods Enter the values that define the maximum and minimum levels to measure. These parameters are Max Level and Min Level, and must be set correctly before any of the calibration steps.

Collection of data points nearest the maximum (but not higher) and minimum (but not lower) levels occurs during calibration. See the procedure on page 3-9 to collect these data points.

Table 3.1 Calibration methods

Standard method Simple methodUse if the gauge is required to be repeatable and precisely or linearly indicate the level of process throughout the span.

Use if the gauge is only required to be repeatable, but need not precisely indicate the level of process.

Use for vessels in which it is critical to know the precise level.

Typically used for surge bins or other vessels under control that maintains one level.

The linearizer type chosen must be Non-linear table.

The linearizer type chosen must be Linear table.

Note: The simple method produces a measurement indication that is repeatable but not precise between the Cal Low Level and Cal High Level points. The measurement indication is not linear with respect to the actual process level.

In some applications, precision is not critical and this method is valid.


Calibration

The figure illustrates the effect on the final output of using the non-linear table vs. the linear table for the linearizer. Using the non-linear table linearizer in the standard method produces a linear output.

Standard calibration methodThis method requires collecting intermediate data points.

Indicated Level

MaximumLevel

Standard

Simple

Maximum LevelActual LevelMinimum

Level

MinimumLevel

Cal Low Counts

Cal High Counts

Min Level

Cal Low Level

Cal High Level

Max Level

Actual Level (engineering units)

Min and Max Level data points

Linearizer data collected at various process levels

Intermediate data pointsRaw Sensor Counts


Calibration

The internal software calculates a linearizer curve based on data points. The curve is the most accurate between the Cal Low Level and Cal High Level.

So, it is best to take the Cal Low and Cal High samples as close as possible to the Min Level and Max Level to maximize the accuracy within the span.

The linearizer curve maps on 2 axes so it indicates % Count Range vs. % Span.

To construct the linearizer table, a data point calculates for every 2.5% of the span. View or edit these points in the Linearizer table screen.

Cal Low Counts

Cal High Counts

Min Level

Cal Low Level Cal High Level

Max Level

Actual Level (engineering units)

Standard

Simple

Raw counts vs. actual count level with linearizers

Raw Sensor Counts

% Count Range

100%Standard

Simple

100%

% Span

0%

0%

% Count range vs. % Span (in linearizer table)


Calibration

Simple calibration method This method does not require collecting intermediate data points.

The internal software calculates a straight line between the Min Level and Max Level based on the Cal Low Level and Cal High Level.

Choosing the linearizer typeThe gauge’s response curve is non-linear, due to the measurement method of radiation transmission. The linearizer determines the shape of the curve between the endpoints.

The gauge’s linearizer type is part of the signal processing necessary to produce a linear final output with respect to the change in level of process material.

Table - Non-linearUse this type for a standard method calibration. It takes into account the inherent non-linearity of a nuclear transmission measurement, so it is more accurate than the linear table.

The non-linear table can use data from:

• Linearizer lookup table (data points that you collect and enter during the calibration process)

• Linearizer data from an earlier model Ohmart/VEGA level gauge

Table - LinearUse this type for a simple method calibration. This type lets you use a linear (straight-line) set of data for a linearizer lookup table. You do not need to collect linearizer table data points. The straight-line linearizer calculates from the high and low-level calibration points.

This requires you to:

1. Perform a two point calibration.

2. Calculate the calibration.

It is less accurate because it does not compensate for the non-linearity of a radiation transmission measurement.


Calibration

Procedure 3.2: To choose a linearizer type

Checking the gauge repeatabilityCheck the gauge’s measurement repeatability before performing the calibration.

To check the repeatability of the sensor, perform a data collection 3 – 4 times on the same level. If the sensor counts vary widely, you should increase the Data collection interval parameter.

Perform a data collection to enable simple measurement of the process, without altering the calibration or standardization values. It lets the system measure the process and report the number of sensor counts.

1. Select Setup | Gauge Setup | Linearizer Type.

2. Click Table - Non-linear or Table - Linear.


Calibration

Procedure 3.3: To perform a data collection

Calibration procedures

* Perform these data collection steps in any sequence, depending on your ability to empty and fill the vessel.

1. Select Calibrations | Data Collect.

2. Click Execute.

3. Set the process to a known point.

4. Click Start.

After the data collection, the number of counts output by the gauge appears.

5. Click Accept.

6. Repeat as often as necessary if checking repeatability.

Standard method Simple methodIncludes these steps (see the following pages):1. Setting the low level and collecting Cal Low data*2. Setting the high level and collecting Cal High data*3. Collecting the linearizer table data*4. Calculating the linearity5. Calculating the calibration

Skips steps 3 and 4.


Calibration

If using the standard method, it may be helpful to record the sensor counts and levels at each step:

1 Setting the low level and collecting Cal Low dataYou must:

1. Use the gauge to measure the low process level.

2. Enter the actual level.

This sets the low end (sometimes called 0) of the calibration curve. Perform this procedure before or after setting the high level.

Before starting the Cal Low data collection:

Fill vessel to the low level.

Have the actual level value ready to enter.

Table 3.2 Standard calibration sensor counts and levels record

Data type Sensor countsActual level (engineering units)

Cal low level (usually empty)Linearizer data point 0

123456789

Cal high level (usually full)Linearizer data point 10

Note: Perform a data collection for the low and high level within ten days of each other for a good calibration. The low and high values must be > 10% of the process span apart for the most accurate calibration. Increasing the process span usually increases the gauge accuracy.


Calibration

Procedure 3.4: To set the cal low level

2 Setting the high level and collecting Cal High dataYou must:

• Use the gauge to measure the high process condition.

• Enter the actual level.

This sets the gain of the calibration curve. Perform this procedure before or after setting the low level.

Before starting the Cal High data collection:

Fill vessel with high process, or close the source holder shutter to simulate high process.

1. Select Calibration | 2 Point Calibration | Cal Low Collect.

2. Click Start.

3. Click Accept.

4. Enter the actual value in engineering units.

5. Click OK.

Note: You must perform a data collection for the low and high level within 10 days of each other for a good calibration. The low and high values must be > 10% of the process span apart for the most accurate calibration. Increasing the process span usually increases the gauge accuracy.


Calibration

Have the actual level value ready to enter.

Procedure 3.5: To set the cal high level

3 Collecting the linearizer table data

This step lets you collect data points between the high and the low calibration points so the gauge calculates a response curve based on your data.

Before collecting the linearizer table data:

Prepare to set the level and take data for ≤10 levels (including the Cal Low and Cal High levels).

Prepare to enter the levels into the gauge.

You can collect linearizer table data with the data collection for the Cal Low and Cal High levels.

1. Select Calibration | 2 Point Calibration | Cal High Collect.

2. Select Start.

3. Click Accept.

4. Enter the actual level process value in engineering units.

5. Click OK.

Note: The simple method skips this step.


Calibration

Procedure 3.6: To collect linearizer table data

4 Calculating the linearity

After collecting the data for a linearizer table, the transmitter uses the data to calculate a new calibration linearizer table. The Calc linearity function initiates this calculation.

You must perform this step before the Calculate Calibration step (see the next section).

Before calculating the linearizer:

1. Select Calibration | Linearizer Data Pt | Create Data Point.

2. At the prompt, enter the actual known level of process.

3. Accept or reject the results when they appear.

4. Repeat procedure for all available levels..

Note: The simple method skips this step.

Note: Include the data for the Cal Low and Cal High with the linearizer data before you perform Calculate linearity. If you did not perform a linearizer data collection while the process was at the levels for Cal Low and Cal High, you can manually add those values to the linearizer data.

To add a data point to the linearizer data, you must know the level in engineering units and the sensor counts.


Calibration

1. Select non-linear table for the linearizer curve.

2. Collect linearizer data.

Procedure 3.7: To calculate the linearizer

5 Calculating the calibrationProcedure 3.8: To calculate the calibration

Repeating the calibrationTypically, the system requires only periodic standardization to compensate for drifts over time.

However, these events require you to repeat the calibration:

• Measurement of a new process application (contact Ohmart/VEGA for recommendation)

• Process requires a new measurement span

• Entering a new measurement span setting into the software

• Installing a new radiation source holder

• Moving the gauge to another location

• Changes to the process vessel (example: lining, insulation, or agitator)

• Excessive buildup or erosion of vessel that standardization cannot compensate for (check standardize gain)

• Standardize gain > 1.2 after a standardization, indicating it made a 20% adjustment from the last calibration

1. Select Calibration | Linearizer Data Pt | Recalculate.

2. Click OK to proceed with the linearity calculation. The linearizer table calculates based on the level values.

1. Select Calibration | 2 Point Calibration.

2. Click Calculate Results.

3. Click OK.

4. Click OK.


Calibration

Periodic process standardizationStandardization adjusts the system by resetting one point of the calibration curve to an independently measured or known level.

The frequency of standardization depends on several factors, including the reading’s accuracy.

During the standardization procedure, the system displays:

• A default value for the standardization condition

• A prompt to enter the actual level of the standardization condition

Standardization reminderIf you enable the standardization due alarm, the gauge produces an alarm when standardization is due. The standardize interval is programmed in Setup | Cal Parameters.


Calibration

Procedure 3.9: To standardize the gauge

1. Select Calibration | Standardize.

2. Click Execute.

3. Click OK.

4. Enter the reading.

5. Click Start.

6. Click Accept.

7. Enter the process value.

8. Click OK.

9. Click OK.


C H A P T E R

4Chapter 4ADVANCED FUNCTIONS

Functions not required for normal operation of the gauge are in the Ohmview2000 software under the Diagnostics and Gauge Info tabs. These functions are primarily for use by Ohmart/VEGA personnel for advanced troubleshooting and repair.

Process chainThe process chain is a description of the gauge software’s calculation of a level measurement from a radiation reading. In the Process Chain tab, you can view intermediate values of the calculation to verify proper functionality of the software.

Note: Ohmart/VEGA strongly recommends that you ask our advice before using any advanced function.


Advanced functions

Table 4.1 Process Chain tab — display values

Value DescriptionSensor Temperature The internal probe's measurement of the sensor temperature.Sensor Counts True counts output from the sensor, but before application of:

• Temperature compensation• Standardize• Sensor uniformity gains

Temp Comp Counts The temperature-compensated counts that are sensor counts with application of temperature compensation.

Raw Counts Temperature compensated counts with application of uniformity gain.Adjusted Counts Sum counts that are raw counts plus auxiliary raw counts. In most

applications, this does not use auxiliary input, so sum counts = raw counts.

Source Decay Counts Sum counts with application of source decay gain.Standardize Counts Displays standardize counts that are source decay counts with

application of standardization gain.Percent Count Range The compensated measurement counts that express as a percent of the

counts at the high and low-endpoints of the calibration (determined with the two point calibration.) This quantity shows where the current measurement is in relation to the total count range.% count range = 100 x (CL - CS) / (CL - CH)whereCS = sum countsCL,CH = counts at Cal Low level and Cal High levelCL-CH = counts range

Percent Process Span The measurement value as a percent of the measurement span. Enter the maximum and minimum level values in the Setup tab.A graph of percent count range vs. percent process span indicates the non-linearity of the radiation transmission’s measurement. If using a table linearizer, the values in the table are percent count range and percent process span.

Unfiltered PV The level in inches without the time constant or rectangular window filter.Uncompensated PV The level of process before any process compensation.Final PV The process value in engineering units after applying the filter.This value

relates to the current loop output.Aux Counts The frequency-input counts from optional auxiliary input.Filtered Aux Counts The filtered auxiliary counts. Enter the filter dampening value for the

auxiliary input’s filter time-constant.


Advanced functions

Gauge Information

Process Variables tab

Table 4.2 Process Variables tab — display values

Value DescriptionMin PV The value, in process units, as entered in the setup tab. Use this to

calculate the measurement span.Max PVCounts Low The temperature and sensor uniformity gain compensated counts

from the sensor at the Cal low level. Determining the Cal low level occurs during the calibration.

Counts High The temperature and sensor uniformity gain compensated counts from the sensor at the Cal high level. Determining the Cal high level occurs during the calibration.

Sensor Temp Comp Gain

The current value of the temperature compensation gain. Use this to adjust for inherent sensor output change with temperature.

Uniformity Gain The current of the uniformity gain. Use this to force all level sensors to output the same counts at a given radiation field. Most level applications do not use uniformity gain and use a default of 1.0.

Source Decay Gain The current value of the source decay gain. Use this to compensate for the natural decay of the radiation source, which produces a lower field over time.

Stdz Gain The current value of the standardize gain that adjusts with each standardize procedure.

HV Setting The set point for the sensor high voltage.


Advanced functions

Gauge Info tab

Table 4.3 Gauge Info tab — additional display values

Procedure 4.1: To check the equipment version, serial numbers, and temperature coefficients

Scintillator sensor voltage

Firmware version on the FLASH

Hardware’s version number

GEN2000 CPU board’s serial number

GEN2000 unit’s serial number

Sensor Coefficients T0 – T3

Value DescriptionSensor Coefficients The algorithm that compensates for variations in measurement

output with changes in temperature uses temperature coefficients. The factory determines the coefficients through rigorous testing. You cannot change them through normal operation.

1. Select Gauge Info | Gauge Info.

2. The Gauge Info tab appears.


Advanced functions

Min/Max History tabThe Min/Max History displays the minimum and maximum values for parameters since the last min/max reset.

Table 4.4 Min/Max History tab — display values

You can reset these values so they record from the time of the reset.

Procedure 4.2: To reset the min/max history

Value DescriptionSensor Counts The raw uncompensated counts from the detectorAux in min/max The auxiliary input counts (if used)Sensor Temperature The internal temperature of the scintillator sensor in the level gaugeLast reset The date of the last min/max reset

1. Select Gauge Info | Min/Max History.

2. Click Reset History.


Advanced functions

New hardware or corrupt EEPROMThe gauge contains 2 EEPROMs (electrically erasable programmable read only memory) that store all data specific to that sensor/electronics pair for the installation.

The EEPROMs are located:

• On the CPU board

• On the sensor board

Each EEPROM contains a backup of the other. The system monitors both EEPROMs at power-up to ensure accurate backups.

If you install a new CPU board, the EEPROM performs a backup of information on the CPU and the sensor boards do not match. The software signals the discrepancy with an error message. The gauge does not perform a backup in case the discrepancy is due to EEPROM corruption rather than new hardware.

New Hardware tab

Note: Only use the New hardware functions if you replace the CPU or sensor assembly. These functions are unnecessary if installing a new detector assembly, which includes the CPU board and the sensor assembly.


Advanced functions

Responding to the New hardware found message

When new hardware is installedWhen you install a new CPU board or sensor assembly, you must verify installation in Ohmview 2000 to enable new backups of the EEPROMs.

Procedure 4.3: To verify the “New Hardware Found” message

When new hardware is not installedIf the error message New hardware found appears, an EEPROM is probably corrupt.

The messages “CPU EEPROM Corrupt” or “Sensor EEPROM Corrupt” may also appear in the history.

Usually, you can repair the corruption using the EEPROM backup.

Procedure 4.4: To repair the corruption using the EEPROM backup

Test modesIn the test modes, the transmitter stops measuring the process material and allows manual adjustment of critical variables for troubleshooting.

The test modes function independently, but you can use them in combination to test multiple variable effects.

All test modes time out after one hour if you do not exit.

1. Select Diagnostics | New hardware | New CPU or New Sensor.

2. Click OK.

Caution: If you suspect an EEPROM is corrupt, please call Ohmart/VEGA Field Service for advice before performing the following procedure.

1. Select Diagnostics | New Hardware | No New Hardware.

2. Click OK.

Caution: While in a test mode, the gauge is not measuring process, so its current output does not reflect the process value. If your DCS is controlling from the gauge's current output, remove the system from automatic control before entering a test mode, as prompted by the software screens.


Advanced functions

Test

Current Loop Test (milliamp output)This mode manually forces the current output to a specified value. This is useful for verifying the current loop calibration. To calibrate the current loop, see Chapter 3: Calibration.

Procedure 4.5: To perform a current loop test

Sensor TestThis mode simulates the sensor output at a number of raw counts you define. This is before application of:

• Temperature compensation

Test modes available:

1. Select Diagnostics | Test | Current Loop Test.

2. Click Enter.

3. Remove the gauge from control.

4. Enter the current loop test value.

5. Click OK.

The transmitter functions in this mode until it times out (1 hour), or you click Exit and OK.


Advanced functions

• Sensor uniformity gain

• Standardize gain

The true sensor output is ignored while the transmitter is in sensor test mode.

This mode is useful for verifying the electronics and software response to input counts without having to:

• Change the process

• Shield the source

• Vary the radiation field

While in this mode, after entering a number of counts, it may be useful to look at the Process Chain tab to view the variables affected by the raw counts value.

Procedure 4.6: To perform a sensor test

Auxiliary Input TestThis mode simulates the auxiliary input frequency at a user-defined number of counts. The effect of auxiliary input counts depends on the auxiliary input mode.

Examples:

• Temperature probe

• Flow meter

• Second transmitter

While in this mode, after entering a number of counts, it may be useful to look at the Process Chain tab to view the variables affected by the auxiliary input counts value.

Procedure 4.7: To perform an auxiliary input test

1. Select Diagnostics | Test | Sensor Test.

2. Click Enter.

3. Remove the gauge from control. Enter the value of the new counts to force.

4. Click OK.


1. Select Diagnostics | Test | Auxiliary Input Test.

2. Click Enter.

3. Remove the gauge from control. Enter the auxiliary counts.


Advanced functions

Relay TestThis mode manually toggles the relay On or Off to test the contacts. This is useful for verifying whether alarm annunciators are functioning.

Procedure 4.8: To perform a relay test

Temperature TestThis mode manually forces the sensor’s temperature probe output to a specified value. This is useful for verifying the scintillator sensor temperature compensation.

Procedure 4.9: To perform a temperature test

4. Click OK.


1. Select Diagnostics | Test | Relay Test.

2. Select Energize relay or De-energize relay.

3. The transmitter functions in this mode until it times out (1 hour), or you click Exit.

1. Select Diagnostics | Test | Temperature Test.

2. Click Enter.

3. Remove the gauge from control. Enter the value of the new temperature to force.

4. Click OK.

5. The transmitter functions in this mode until it times out (1 hour), or you click Exit and OK.


Advanced functions

Selecting the transmitter’s type and location

Gauge Setup tab

TypeThe GEN2000 density and level gauges look similar and use the same software. If your level transmitter indicates Density, it was set incorrectly for a level application.

Procedure 4.10: To select the transmitter’s type

LocationThe local transmitter refers to a gauge that has its sensor electronics and processing electronics all contained in the same housing.

Set a gauge to Remote if the sensor electronics and processing electronics are in separate housings and the process signal connects to the auxiliary input of the processing electronics.

1. Select Setup | Gauge Setup | Gauge Type.

2. Select Level.


Advanced functions

Procedure 4.11: To select the transmitter’s location

1. Select Setup | Gauge Setup | Transmitter Location.

2. Select Local or Remote.


C H A P T E R

5Chapter 5DIAGNOSTICS AND REPAIR

Software diagnosticsThe level transmitter system can alert users to potential problems by:

• Posting messages on the Ohmview 2000 message screen

• Energizing the output relay

• Distinctly changing the current loop output

• Tracking the current status and history in the Gauge status screens

Table 5.1 Alarm types

Name DescriptionDiagnostic alarm

Provides information about the level gauge system and alerts users when periodic procedures are due.

Analog alarm Sets the current loop mA output to 2 mA or 22 mA when the detector outputs 0 counts.

Process alarm

The process alarm lets the relay output trip when the process level is above (high limit) or below (low limit) a setpoint.

X-ray alarm Distinctly changes the current loop mA output in response to a marked increase in the radiation field. This prevents control problems when external radiographic sources are in the area for vessel inspections.


Diagnostics and repair

Gauge Status tab

Diagnostic alarms and HART messagesDiagnostic conditions that are currently in alarm alert users by:

• Diagnostics screens in the Messages box on the main Ohmview 2000 screen

• HART messages that appear when a HART device connects if the diagnostic condition is selected in Alarms | Diagnostic Alarm

• Relay output if it is set as a diagnostic alarm relay in Alarms | Relay Setup | Relay Functions

Table 5.2 Alarm type outputs

Diagnostic Analog Process X-rayOption to trigger relay

X X X

Display HART message

Optional

Current loop output affected

X X

Gauge status and gauge history

X



Relay Setup tab

Gauge status diagnostics screens• To check the system’s present status, select Diagnostics | Diagnostics tab.

• For historical information, select the Diagnostic History and STDZ History tabs.

Some conditions are self-repairing (example: RAM and EEPROM corruption). Therefore, these may appear in history screens but not diagnostic screens.

Acknowledging diagnostic alarmsDiagnostic alarms turn off when the problem is solved, except these alarms:

• Source wipe due

• Shutter check due

• Standardize due

Perform the procedure to acknowledge them.

Note: If the relay is set as a diagnostic alarm, you must acknowledge all diagnostic alarms to reset the relay.



Diagnostic alarm messagesActive alarm messages may appear on the Ohmview 2000 menu if the alarm condition is selected. You can select individual alarm conditions in the Alarms | Diagnostic Alarm Enable tab.

When a HART device initially connects to the gauge, any conditions in alarm appear on the screen.

Table 5.3 Diagnostic alarm conditions

Diagnostic check and Normal/Error conditions

HART messageDiagnostic description Action

RAM Status – Pass/Fail

RAM corruptRAM memory corruption occurred and was resolved internally. Repeated triggering of this alarm suggests a hardware problem.

Consult Ohmart/VEGA Field Service.

Sensor EEPROM – Pass/Fail

Sensor EEPROM corruptA critical memory corruption occurred on the sensor pre-amp board EEPROM that may not be resolved internally.

To check for recurrence, acknowledge the alarm. Cycle power to the unit.If the alarm recurs, there is a hardware problem. Perform the procedure to repair the corrupted EEPROM on page 4-7.

Real Time Clock Status – Pass/Fail

Real time clock failThe clock failed. This can cause a miscalculation of timed events. (If the gauge had no power for > 28 days, reset the time and date.)

Reset the time and date. If they do not reset, call Ohmart/VEGA Field Service.

Sensor Temp Probe – Pass/Fail

Sensor temp probe failThe sensor temperature probe may not be functioning, which results in erroneous measurements.

Verify the sensor temperature on the Gauge Info | Min/Max History tab. If the temperature reads -0.5 °C constantly, the probe is broken and the sensor assembly may need replacement. Call Ohmart/VEGA Field Service.

Source wipe due – No/Yes

Source wipe due Acknowledge the alarm by logging a shutter check in the Source Functions tab. See page 5-14.

CPU EEPROM – Pass/Fail

CPU EEPROM corruptA non-critical memory corruption occurred on the CPU board EEPROM that may not be resolved internally.

To check for recurrence, acknowledge the alarm. Cycle power to the unit.If the alarm recurs, there is a hardware problem. Perform the procedure to repair the corrupted EEPROM on page 4-7.



Alarm type 1 – Not used

Not used in standard software. Consult Ohmart/VEGA special software.

Alarm type 2 – Not used

Not used in standard software. Consult Ohmart/VEGA special software.

Sensor Status? – Pass/Fail

Sensor fail<1 count seen in the last 10 seconds. (Configurable by Field Service.) Indicates the sensor is malfunctioning.

Call Ohmart/VEGA Field Service.

Sensor Voltage Status – Pass/Fail

Sensor high voltage failThe high voltage on the PMT is outside the usable range.


Standardize Due – No/Yes

Standardize Due Perform a new standardization

Source Wipe Due – No/Yes

Source Wipe Due Perform a source wipe. Acknowledge it on the Source Functions tab.

Shutter check due? – No/Yes

Shutter Check Due Perform a Shutter Check. Acknowledge it on the Source Functions tab.

New hardware found? – No/Yes

New hardware found – The CPU board detects a configuration mismatch. The CPU board or sensor assembly may have been replaced, or one of the EEPROM configurations is erroneous.

Contact Ohmart/VEGA Field Service. See page 4-8.

Process out of range? – No/Yes

Process out of measurement range – The current process value is not within the limits set by the Max level and Min level in the gauge span settings.


X-Ray Alarm – No/Yes

Note that there are high levels of x-ray in your area that may be affecting process measurement.

Contact Ohmart/VEGA for further information.

Table 5.3 Diagnostic alarm conditions (continued)

Diagnostic check and Normal/Error conditions

HART messageDiagnostic description Action



Analog alarmIf the current loop output (analog output) is stable at 2 mA or 22 mA, the analog alarm is set.

The analog alarm is set when the counts from the detector falls below a set threshold, indicating that the detector is not outputting enough counts to make a meaningful measurement. This is known as 0 counts.

If the analog alarm is on, verify:

Source holder shutter is in the On or Open position to create the required radiation field.

Extreme build-up on walls or other material shielding the detector from the radiation field.

Damage or disconnection of electrical connections from the sensor assembly to the CPU board.

Process alarmThis alarm alerts users when the process level is above (high limit) or below a setpoint (low limit). Enter the choice of low or high limit and the setpoint on the Alarm | Relay Setup tab.

This alarm works only with the output relay. HART messages, gauge status diagnostics, and history information are not saved for this alarm.

The gauge acknowledges or resets the process alarm when the process value returns to the setpoint value. Depending on your usage of the process alarm relay, you may install a process alarm override switch to manually turn off an annunciator when the gauge relay energizes.

X-ray alarmThis alarm compensates for falsely indicated process values that occur when the gauge detects external radiographic sources (example: vessel weld inspections often use portable radiographic (x-ray) sources). X-rays that the gauge detects can cause a false low reading and adversely affect any control based on the gauge output.

This alarm can:

• Alter the current loop output to indicate the alarm condition

• Trip the output relay, if it is configured to do so



The level gauge enters the x-ray alarm condition when it detects a radiation field above a set threshold. The gauge sets the current loop output at its value 10 seconds before the condition. It periodically dithers the output about the average, cycling until the radiation field is back to the normal level or until a time-out period of 60 minutes.

The standard x-ray alarm only triggers when the counts are greater than the Cal Low count value. These counts are found on the process variable menu. If the x-ray source is configured so the counts increase but do not exceed the Cal Low counts, the x-ray alarm does not trigger and the gauge reads the x-ray interference as a true process shift.

Auxiliary x-ray alarmTo detect x-rays that are causing process changes, a second detector can be placed outside of the radiation beam of the primary detector. The second detector only monitors x-ray interference, and has a frequency output that wires to the auxiliary input of the primary detector.

The primary detector's programming triggers the x-ray alarm when the counts of the secondary detector are above a threshold.

Call Ohmart/VEGA for more information.

output 10s before x-ray

current loop output (mA)

Dither level

Dither time

Cycle period

time (ms)

X-ray interference alarm output



History information

Diag History

The Diagnostics | Diag History tab displays information about critical events.

Use this information to determine whether a problem recently occurred and was internally repaired (example: EEPROM corruption).

TroubleshootingTwo circuit boards in the level gauge are field-replaceable.

You can view the newestand oldest trigger records

for these events:

Caution: A minimum of 10 minutes should be allowed after de-energizing, before opening the GEN2000 for internal inspection to permit cooling and full capacitor discharge.



Circuit board identifications

Power supply board

RS-485 ground (if applicable)

Mounting bracket

GEN2000 circuit board identification

External housing

ground screw

Internal housing ground screw

CPU board



Test pointsLocated on the power supply and CPU board.

Power Supply Board

CPU Board LEDs

(simplified component layout)

Table 5.4 Power supply board test point labels

Label DescriptionH1 HART connectionH2 HART connectionTP1 Isolated groundTP2 Loop current test point 200 mV/mA loop current. Referenced to isolated ground.

Table 5.5 CPU test point labels

Label DescriptionCount Raw input signal coming from the preamplifier.GND Logic groundU5 pin 8 +5 V power supply test points. Referenced to logic ground.



JumpersJumpers JP1 and JP2 on the power supply board set the current loop source or sink mode.

The level gauge does not use jumpers J1 – J4 on the CPU board.

LED indicators

CPU board LED indicatorsUse the LED indicators on the CPU board to check the basic functioning of the gauge. They are visible when you remove the explosion-proof housing pipe cap.

Note: Do not change the jumpers from the current setting without calling Ohmart/VEGA Field Service.

Table 5.6 Jumper settings

Mode Gauge current loop Jumper settingSource mode Self-powered JP1 1-2, JP2 2-3Sink mode DCS-powered JP1 2-3, JP2 1-2

Table 5.7 Power supply LED indicators

LED DescriptionNormal Condition Error condition Recommendation

+6 V +6 V DC voltage level to electronics

ON OFF – electronics are not receiving +6 V DC voltage required for functioning.

Verify +6 V on test points. Check fuse on power supply board. Check power input terminals 1, 2.

+24 V

Analog output loop voltage

ON OFF – 24 V not present on 4 – 20 mA output.4 – 20 mA output and HART communications are bad.

Check loop wiring and jumpers JP1, JP2 on power supply board. Replace power supply board.

Relay

Relay condition indicator

ON = relay is energized.OFF = relay is de-energized.

None Check against relay output terminals 3, 4, and 5. If no relay output, replace power supply board.

Note: If the LED band displays the Memory Corrupt pattern, call Ohmart/VEGA Field Service to report this condition. The gauge does not operate if the FLASH chip is corrupt.

CPU LED memory corrupt pattern

FIELD

MEM

HART

CPU

AUXHV

FIELD HV

AUX

CPU

HART

MEM

On

Blinking

Off

Normal LED pattern Memory corrupt pattern



Table 5.8 CPU board LED summaryLED Description Normal condition Error condition RecommendationMem Memory

corruption (EEPROMs and FLASH)

OFF 1 blink: CPU EEPROM corrupt2 blinks: Sensor EEPROM corrupt3 blinks: Both EEPROMs corrupt4 blinks: RAM corrupt 5 blinks: Memory mismatchON solid: combination of errors

Check software diagnostics. Call Ohmart/VEGA Field Service.

HART HART communication indicator

ON – blinks when receiving HART messages

None Check HART device connection on loop and HART device functioning.

CPU Central processing unit on CPU board

Blinks at rate of 1 time per second

LED does not blink. CPU not functioning.

Check power input. Replace CPU board.

Aux Auxiliary input frequency signal indicator

Blinks if auxiliary input present. OFF if no auxiliary input present

None Check auxiliary input wiring terminals 11 and 12 with a meter for frequency signal. Check auxiliary input equipment.

HV Sensor high voltage

ON – high voltage is within specification

OFF – high voltage is outside of specification

Call Ohmart/VEGA Field Service

Field Radiation field indicator

Cycles in proportion to radiation field intensity at detector. ON for 10 seconds for each mR/hr, then off for 2 seconds. (Can use LED 5 that blinks 1 time/sec to time LED1 for field indicator.)

None Check for closed source shutter, buildup, and insulation.



Maintenance and repair

Periodic maintenance scheduleSince the Ohmart/VEGA gauge contains no moving parts, very little periodic maintenance is required. We suggest this schedule to prevent problems and comply with radiation regulations:

Source Functions

Table 5.9 Periodic maintenance schedule

Description Frequency ProcedureStandardize As required by process conditions,

usually at least once a monthCalibration chapter

Source holder shutter check

Every 6 months unless otherwise required by the appropriate nuclear regulatory body

Radiation safety instructions shipped separately with source holder and following instructions

Source wipe Every 3 years unless otherwise required by the appropriate nuclear regulatory body

Radiation safety instructions shipped separately with source holder and following instructions



Recording the source wipe and shutter checkYou can use the gauge’s diagnostic alarms to remind you when a source wipe and shutter check are due. If you do, you must record the source wipes and shutter checks in the software to acknowledge the alarm and reset the timer.

Perform this procedure after a source wipe or a shutter check.

Procedure 5.1: To record a source wipe or shutter check

Procedure 5.2: To change the due date of source wipe or shutter check

Field repair proceduresVery few parts are field repairable, but you can replace entire assemblies or boards. These parts are replaceable:

• CPU circuit board

• Power supply circuit board


1. Select Setup | Source Functions.

2. Click Record Wipe or Record Shutter Check.

1. Select Setup | Source functions.

2. Change the number of days in the Wipe Interval or Shutter Check Interval field.

3. Click OK.

Note: Use great care to prevent damage to the electrical components of the gauge. Ohmart/VEGA recommends appropriate electrostatic discharge procedures.



Spare partsSee page 1-13 for contact information. Ask for parts and repairs.

Replacing the CPU or Power supply boardYou may have to replace a circuit board if there is damage to one of its components. Before replacing a circuit board, check the troubleshooting flowcharts or call Ohmart/VEGA Field Service to be sure a replacement is necessary.

The sensor EEPROM contains a backup of the CPU board EEPROM. After replacing the CPU board, you must perform a memory backup to update the CPU board’s EEPROM with the information in the sensor board EEPROM.

Procedure 5.3: To replace the CPU or power supply board

Table 5.10 Spare parts

Description Part NumberPower supply board 241519CPU board 239622125 mA fuse on power supply 2386612A fuse on power supply 240539HART Modem kit 237857Ohmview 2000 Software 243008

1. Shut off the power to the gauge.

2. Remove the housing’s cover.

3. Remove the plastic electronics cover.

4. Remove the terminal wiring connector.

5. Remove the screws from the top hold-down plate.

6. Carefully pull the 2 boards (still attached to their mounting bracket) out of the housing. As you pull the CPU board out, try not to damage the ribbon cable that attaches to the sensor.

7. Remove the cable between the CPU and power supply boards.

8. Remove the appropriate board from its mounting bracket and replace it with a new board. If changing the CPU board, disconnect the sensor connector from the CPU board. When you install the new CPU board, reconnect the sensor connector.

9. Reconnect the cable between the CPU and power supply boards.



Returning equipment for repair to Ohmart/VEGAHave this information ready:

Product model that is being returned for repair

Description of the problem

Ohmart/VEGA Customer Order (C.O.) Number

Purchase order number for the repair service

Shipping address

Billing address

Date needed

Method of shipment

Tax information

10. Carefully install the circuit boards in the housing. Try not to damage the sensor cable on the CPU board.

11. Secure the brackets back to the hold-down plate.

12. Reconnect the terminal wiring connector.

13. Install the plastic electronics cover.

14. Install the housing cover.

15. Apply power to the unit. Connect a HART communicator to the unit (a HART handheld or the Ohmart/VEGA software program) to verify that the unit is operational.

Note: If you change the CPU board, a New Hardware Found error message appears when you connect with the HART communicator. This is normal. Follow the procedure on page 4-7 for installing new hardware so the non-volatile memory on the CPU configures properly.



Procedure 5.4: To return equipment for repair

1. Contact your local Ohmart/Vega representative, using the information on page 5-20, and ask for repair service.

2. Ohmart/VEGA assigns the job a material return authorization (MRA) number.

3. Indicate the MRA on the repair service purchase order.

4. Clearly mark the shipping package with the MRA number.

5. Send the confirming purchase order and the equipment to your local representative, to the attention of the repair department. See Customer Service on page 1-13 for contact information.

Note: You must first contact Ohmart/VEGA and receive a material return authorization number (MRA) before returning any equipment. Ohmart/VEGA reserves the right to refuse any shipment not marked with the MRA number.



LFXG-H Installation and Operation Guide Index-1

AAcknowledging diagnostic alarms, 5-3Adj counts, 4-2Advanced Functions, 4-1Advanced Fxns, 4-1alarm

analog alarm, 5-6Alarm type outputs, 5-2Analog alarm, 5-1analog alarm

acknowledging, 5-6analog output. See current loop output, 3-1

output fixed at 2mA or 22mA, 5-6applications, 1-5Auxiliary Input Test mode, 4-11Auxiliary x-ray alarm, 5-7

Ccalibration

current loop (analog output), 3-1initial simple method of, 3-4initial. See initial calibration, 3-3process, 3-3

Counts High, 4-3Counts Low, 4-3CPU board

jumpers, 5-11LED indicators, 5-11replacing, 5-14, 5-16

CPU EEPROM corrupt, 4-7alarm acknowledge, 5-3, 5-4in diagnostic history, 5-8

CPU EEPROM statusdiagnostics check, 5-4

CPU serial number, 4-4current loop

calibrating on the bench, 2-1, 2-2calibration, 3-1output fixed at 2mA or 22mA, 5-6output test mode, 4-8power source or sink mode, 5-11

Customer Order (C.O.) Number, 1-10required for repairs, 5-17

DData collection interval

using data collect on sample to check interval, 3-9DCS, 2-9

device description, 1-8Diagnostic alarm, 5-1diagnostic alarm

acknowledging, 5-4messages, 5-4resetting relay, 5-3

diagnostic history, 5-8

EEEPROM corruption repair, 4-7

FField service. See Ohmart Customer Service, 1-10Firmware version, 4-4FLASH, 4-4FLASH corrupt

LED pattern, 5-11

Ggain, 3-12Gauge Info, 4-4Gauge Info tab, 4-4ground screw, internal and external, 2-5

Hhand-held terminal, 1-8Hardware version, 4-4HART Communicator, 1-8HART load resistance, 1-8History information, 5-8HV Setting, 4-3

Iinitial calibration, 3-3

repeating, 3-15theory of, 3-4

Jjumpers, 5-11

LLED indicators, 5-11Level instead of density is indicated. See Select gauge

type, 4-12linear table, 3-8linearizer

Index

Index-2 LFXG-H Installation and Operation Guide

Index

choosing, 3-7linear table, 3-8non-linear table, 3-7

MMax Level, 3-4Max level, 4-3Min Level, 3-4Min level, 4-3Min/Max History, 4-5

NNew hardware

advanced function, 4-6New hardware found

alarm acknowledge, 5-5diagnostics check, 5-5in diagnostic history, 5-8

New hardware found messageresponses to, 4-7

No device found message, 5-11non-linear table, 3-7

OOhmart Customer Service, 1-10

Field Service, 1-10Ohmart Field Service, 5-17Ohmart View software, 1-9

differences with communicator, 1-8Ohmart/VEGA

Parts and repairs, 5-15Ohmart/VEGA Field Service, 1-10

PPeriodic process standardization, 3-15PLC, 2-9Process alarm, 5-1process alarm, 5-6

override switch, 5-6Process chain, 4-1Process out of range

alarm acknowledge, 5-5diagnostics check, 5-5

RRAM corrupt

alarm acknowledge, 5-4RAM status

diagnostics check, 5-4Raw counts, 4-2

Real time clock failalarm acknowledge, 5-4in diagnostic history, 5-8

Real time clock testdiagnostics check, 5-4

Relay Test mode, 4-11repairs

material return authorization (MRA) number, 5-18returning equipment to Ohmart, 5-17

SSD (source decay) counts, 4-2Select gauge location, 4-13Select gauge type, 4-12, 4-13Sensor Coefficients, 4-4Sensor EEPROM corrupt, 4-7

alarm acknowledge, 5-4Sensor EEPROM status

diagnostics check, 5-4Sensor fail

alarm acknowledge, 5-5in diagnostic history, 5-8

Sensor high voltage failalarm acknowledge, 5-5

Sensor Serial Number, 4-4Sensor status

diagnostics check, 5-5Sensor temp probe

alarm acknowledge, 5-4Sensor temperature

in diagnostic history, 5-8Sensor Test mode, 4-10Sensor voltage, 4-4Sensor voltage status

diagnostics check, 5-5shutter check

frequency, 5-14recording when complete, 5-15

Shutter check duealarm acknowledge, 5-5diagnostics check, 5-5

Source Decay Gain, 4-3source wipe

frequency, 5-14recording when complete, 5-15

Source wipe duealarm acknowledge, 5-4

source wipe duediagnostics check, 5-4

spare parts, 5-15specifications

LFXG-H, 1-4

LFXG-H Installation and Operation Guide Index-3

Index

standardization due alarm, 3-16Standardize Gain, 4-3Standardize gain, 3-15storage, 1-3

TTC (temperature compensated) counts, 4-2Temp Comp Gain, 4-3Temperature Test mode, 4-12Test modes, 4-8

UUncompensated level, 4-2

Uniformity Gain, 4-3

Vvessel agitators

effect, 2-3

Xx-ray alarm, 5-1, 5-6

Zzero counts, 5-6

Index-4 LFXG-H Installation and Operation Guide

Index

Documents

Fibreflex Operating Manual