RE20B 1.02 e · Inverted sugar concentration can be converted from the refractive index of the inverted sugar solution measured at 20 °C (nD 20). The RE20B stores conversion tables

RE20B BRIX RefractometerOperating Instructions

METTLER TOLEDO RE20B BRIX Refractometer 3

Contents

Contents Page

1. Introduction ..................................................................................................... 5

2. Safety measures .............................................................................................. 6

3. BRIX, HFCS and Refractive Index .................................................................. 7

3.1 Definition of refractive index ............................................................................... 7

3.2 Definition of BRIX (%) ........................................................................................ 8

3.3 Definition of HFCS42 and HFCS55 (Inverted sugar) ......................................... 8

3.4 Measurement principle ....................................................................................... 9

4. The instrument .............................................................................................. 10

4.1 General overview ............................................................................................. 11

4.2 Keyboard .......................................................................................................... 12

4.3 Display ............................................................................................................. 14

4.4 Measures for correct measurements ............................................................... 15

5. Getting started ............................................................................................... 165.1 Setting up the instrument ................................................................................. 16

5.2 Performing the first adjustment (calibration) .................................................... 17

5.3 Perform a measurement (BRIX, HFCS42 and HFCS55) ................................. 19

6. Sample (Number and ID) .............................................................................. 20

7. Report ............................................................................................................. 20

8. Functions (password protected) ................................................................. 21

8.1 Data File ............................................ (Function 0) .......................................... 21

8.2 Set check .......................................... (Function 1) .......................................... 23

8.3 Periodic Check .................................. (Function 2) .......................................... 25

8.4 Periodic adjustment, resp. calibration (Function 3) .......................................... 26

8.5 Memory Clear .................................... (Function 4) .......................................... 27

8.6 Wait Time .......................................... (Function 5) .......................................... 27

8.7 Decimals ........................................... (Function 6) .......................................... 28

4 METTLER TOLEDO RE20B BRIX Refractometer

Contents

Page

9. Setup (password protected) ......................................................................... 29

9.1 Interface ............................................ (Setup 0) ............................................... 29

9.2 Date and Time ................................... (Setup 1) ............................................... 30

9.3 Name................................................. (Setup 2) ............................................... 31

9.4 Serial/Version number ....................... (Setup 3) ............................................... 31

9.5 LCD Contrast .................................... (Setup 4) ............................................... 31

9.6 International ...................................... (Setup 5) ............................................... 32

9.7 Lock with password ........................... (Setup 6) ............................................... 32

9.8 Beep .................................................. (Setup 7) ............................................... 33

10. Error messages and malfunctions .............................................................. 34

11. Standard and optional equipment ............................................................... 3511.1 Standard equipment ......................................................................................... 35

11.2 Optional equipment .......................................................................................... 35

MemoCard RE20B (Short Instructions) ........................................................................ 36

Annex 1: BRIX Table ...................................................................................................... 37

Annex 2: Temperature corrections for °BRIX refractometer values ......................... 38

Specifications ................................................................................................................. 40


Introduction

1. Introduction

The RE20B BRIX is a refractometer specially designed for quick measurement of BRIX andconcentration of isomerized (invert) sugar solution (HFCS42, HFCS55) with a very highaccuracy. Its measurement range is from 0 to 100 %, with the BRIX values higher than 85 %being extrapolated from the recognized ICUMSA table.

The BRIX measurement gives a result directly in percentage of sucrose in water. TheHFCS42 and HFCS55 give the result in percentage of High Fructose Corn Syrup, theHFCS42 being used for solutions with 42% fructose, the HFCS55 for solutions with 55%fructose.

The measurement is performed at the actual sample temperature and the result compensat-ed to 20 °C according to the ICUMSA table.

Features of RE20B:

• The light source for measurement is an LED which is maintenance free (unlike conventionallight bulb that blows from time to time).

• The measurement prism is made of sapphire, which is strongly resistant against corrosion,very rigid and of high thermal conductivity.

• The border temperature between sample and prism is measured so that highly reliable datacan be expected and obtained as measurement results.


Safety measures

2. Safety measures

The instrument has been tested for the experiments and intended purposes documented inthe Operating Instructions. However, this does not absolve you from the responsibility ofperforming your own tests of the product supplied by us regarding its suitability for themethods and purposes you intend to use it for. You should therefore observe the followingsafety measures.

Measures for your protection

– Ensure that you plug the power cable supplied into a socket which isgrounded! A technical defect could be lethal in the absence of grounding.

– Switch the instrument off and disconnect the power cable if you changeblown fuses! An electric shock could be lethal.

– Do not work in a hazardous area! The housing of the refractometer is notgas tight (explosion hazard through spark formation, corrosion by gasdiffusion into the instrument).

Measures for operational safety

– Do not add samples with hard objects made of glass, metal or ceramics!They could damage the prism.

– Clean the prism immediately after measuring strong acids and bases!These could attack the prism.

– Use only fuses of the specified type if you need to change them!

– Exclude the following environmental influences:• powerful vibrations,• direct sunlight and sharp changes in temperature,• exposure to corrosive gases,• very dusty places,• high atmospheric humidity,• temperatures below 5 °C and above 35 °C,• powerful electric or magnetic fields which influence the power supply

through large load fluctuations!

– If the instrument is not going to be used for a longer period of time, cleanthe prism before stored. It is recommended to use the carton box in whichit was first delivered.

Avoid a place for storage under excessive ambient condition including toohigh or too low temperature, high humidity or heavily dusty area.


Refractive index

=n1n2

sin βsin α

=n1sin αn2

α

β

n1 e.g.of air

n2 e.g.of water

3. BRIX, HFCS and Refractive Index

3.1 Definition of refractive index

The refractive index n of a substance is the ratio of the velocity of a ray of light in vacuum toits velocity in the medium (dimension = 1).

If a ray of light at a particular angle passesfrom, e.g. air to water (optically less denseto optically more dense medium), it chang-es its direction except when the incidentlight is vertical. According to Snell's law ofrefraction, the ratio of the refractive indicesof the two media is proportional to the ratioof the angle of refraction and angle of inci-dence of the ray of light:

If a ray of light passes into an optically lessdense medium from an optically moredense medium, it also changes its direction.If the angle of incidence α is increased, itreaches a critical value at which the ray oflight no longer passes into the optically lessdense medium, the angle of refractionβ = 90 °C. If this "critical angle" is exceeded,total reflection occurs. The critical angle α isused to calculate the refractive index:

As the refraction depends on the wavelength of the incident light, the refractive index ismeasured at the wavelength of the D line of sodium (589.3 nm) as standard and symbolizedby nD.The refractive index depends not only on the wavelength used to measure it, but also on thetemperature of the solution being measured. The standard temperature is 20 °C. If measure-ments are performed at a different temperature, e.g. 25 °C, this must be specified: nD

25.

Critical angle Total reflexion

Air

Water α α αα

β β

β = 90° → sin β = 1


Refractive index

3.2 Definition of °BRIX

The BRIX degree represents the concentration in weight percent of a mixture of puresucrose and water (g sucrose per 100 g solution). It is used as the weight % concentration ofsucrose in general. This concentration is calculated from the measured refractive indexusing the stored concentration table (16th conference of the International Commission ofUniform Methods for Sugar Analysis ICUMSA). The result is given at the standard referencetemperature of 20 °C using the temperature dependence for these solutions from the samesource.So the refractive index and the prism surface temperature are measured and the BRIX iscalculated from the tables.

Note: When substances other than sucrose are present, BRIX is calculated from the totalrefractive index. In such a case the result in BRIX will not indicate the real sucroseconcentration.

3.3 Definition of HFCS42 and HFCS55 (Inverted sugar)

HFCS stands for High-Fructose Corn Syrup. This syrup is manufactured from natural cornsyrup and consists of inverted (or isomerized) sugar: a mixture of dextrose, fructose, maltoseand sucrose. They are classified according to their fructose content. Mainly three differentHFCS are in use: a mixture containing 42% fructose (HFCS42), one containing 55% fructose(HFCS55) and a third one containing 90% fructose (HFCS90).

Inverted sugar concentration denominates the concentration in weight % of an isomerizedsugar solution. Inverted sugar concentration can be converted from the refractive index ofthe inverted sugar solution measured at 20 °C (nD

20). The RE20B stores conversion tables(„Physical Properties Table“, Corn Products, 1991) for two of the mixtures: HFCS42 andHFCS55. Since a temperature compensation table is also stored, temperature compensa-tion is practicable, as long as the sample temperature is within the range of 20 ~ 60.

The relation between inverted sugar concentration and refractive index varies with thecomposition of the inverted sugar. Compositions of the inverted sugars HFCS42 andHFCS55 stored in the RE20B are shown below.

HFCS42 HFCS55

Fructose 42.50% 55.40%

Dextrose 52.50% 40.30%

Maltose 3.00% 3.00%

Sucrose 0.00% 0.00%

Maltotriose DP3 0.70% 0.40%

Oligosaccharide DP4 1.30% 0.90%

Sulfated Ash 0.03% 0.05%


Refractive index

3.4 Measurement principle

The light emitted by the RE20B pass-es through the prism and encountersthe solution. It is partially refracted(angle of incidence < critical angle)and partially reflected (angle of inci-dence > critical angle).

The reflected light is recorded usingan optical sensor (CCD). The bounda-ry between the dark and light areasrepresents the critical angle needed tocalculate the refractive index.

Setup of the measurement systemThe light source is a light emitting di-ode (LED) whose beam passesthrough a polarizing filter, an interfer-ence filter (589.3 nm) and variouslenses before it passes through thesapphire prism and encounters thesample. The reflected light (angle >critical angle) is led via a lens to theoptical sensor, which records the criti-cal angle.

The temperature at the boundary re-gion prism-sample is measured by theembedded sensor.


The instrument

4. The instrument

Front view

Rear view

1. LCD display

2. Keypad

3. Cover lid

4. Measuring cell

5. Prism

6. Printer connector

7. RS-232 connector

8. Power switch

9. AC power connector


The instrument

4.1 General overview

1. LC DisplayThe RE20B has a two-line liquid crystal display that shows measurement results, condi-tions or parameters.

2. KeypadStart measurement, input of measurement conditions or calculation parameters areoperated on these keys.

3. Cover lidIt covers the sample stage for protection and prevents incoming dispersed light. Whenopened it will prevent sample liquid from splashing to the rear of the instrument.

4. Measuring cellThis is the measurement cell. Sample solution is dropped to the centre of the cone. Thesample drops must fill the indicated line which shows approximately 0.4 mL.

5. PrismThe prism is made of sapphire, which is resistant to corrosion and physical damage.

6. Printer connectorThis is for connection of RE20B to an external printer.

7. RS-232C connectorThis is for connection of RE20B to a personal computer.

8. Power switchThe power of RE20B is turned on or off by this switch.

9. AC power connector (IN)Power is supplied by connecting the supplied power cord.

Connect the power cable supplied to the power supply. The instrument will automaticallyadjust its power supply unit to the specific line voltage of your country as long as this is in therange between 100 and 240 V AC.


The instrument

4.2 Keyboard

Description of each key and its function:

Sample Key to set up sample parameters, like sample number and ID/Lot.

Report Key to change print format.There are three (3) kinds of format for printing.(1) Short: Short form for printing minimum necessity of resulting data.(2) GLP: GLP form, which complies with GLP requirements.(3) Variable: User defined printing format.

Method Key to change Method.(1) Method 0: BRIX concentration(2) Method 1: Concentration of isomerized sugar HFCS42(3) Method 2: Concentration of isomerized sugar HFCS55

Display Key to change display or selectet numeric, capital or small letters

Print Key to print the displayed message or parameters

Report

Sample

Method

Display

Print

8DEF

9GHI

4JKL

5MNO

6PQR

1STU

2VWX

3YZ

. 0BLK

-

Func.

Setup

Display

Report

Method

Print

Enter

Reset

Check

Clear

Sample

Esc.

BSCalib.

Measure

7ABC


The instrument

Function Key to selectet following functions:

(0) Data File: Recalculation, auto statistics, deletion of measure-ment results

(1) Set Check: Define the names, values and allowed tolerancesfor the standards to be used for daily and precisioncheck of the instrument

(2) Periodic Check: Define the interval for the precision check(3) Periodic Calib: Define the interval for calibration(4) Memory Clear: Initialize stored data(5) Wait Time: Select time to wait for measurement after [Meas-

ure] key is pressed(6) Decimals: Select a number of digits after decimal

Setup Key to select the setup parameters as follows:

(0) Interface: Set up the RS-232C and the printer(1) Date & Time: Set up date and time(2) Name: Register name (lab or operator)(3) Serial/Ver. No.: Display serial and version No. of the unit(4) LCD Contrast: Adjust brightness of LC display(5) International: Select format for date and select unit (°C/°F) for

temperature(6) Lock: Set up a password for protection(7) Beep: Select beep at the end of measurement or cancel it

Check Key to start the instrument check, daily (always) or precision (onlywhen due)

Calibration Key to start a calibration

Backspace Key to erase one preceding letter or numeral

Clear Key to erase the whole entry (2x to clear names)

Escape Key to return to the main display

Reset Key to abort a measurement or a calibration and to return to maindisplay

Key to start a measurement

Function

Check

Setup

Calib.

BS

Clear

Esc.

Reset

Measure


The instrument

4.3 Display

The RE20B BRIX meter has a two line LCD display with 15 characters per line. When thepower is turned on (power switch on the rear of the instrument), the instrument will diyplaythe following message for a few seconds:

The software version appears for a short time. This soft-ware version can also be displayed under Setup 3 "Seri-al/Version".

After a few seconds the main display will appear:Then it will switch to the ready mode.The number in the left top corner shows the selectedmethod, i.e. method "0".

0 – 9 key Key to enter alphanumeric characters (the selection betweencapital/small letters or numbers is done with the key). To select B, press twice, for C press three times.On the key with the number 0 there BLK (BLK = blank).

Dot and hyphen key

Enter Key to confirm a entry. This key is also called key inthis manual.

Up

Left, Right Keys to move the cursor.

Down

Enter

. –

7ABC

RE20B Vx.xxBrix Meter

0 Ready27.92 °C Brix


The instrument

4.4 Measures for correct measurements

• Check the instrument from time to time measuring reference standards, e.g. from R.P.Cargille Laboratories, Inc. USA.

• Use soft paper towels or washed gauze to remove the sample or dry the prism.

• Use deionized water to clean the cell after aqueous samples. For organic samples use asuitable organic solvent like toluene, ethanol or acetone. If the solvent used doesn'tevaporate readily enough, use a second solvent like acetone to wipe the first one off and geta dry cell.

• Never use cotton wool as its fibres could adhere to the prism and influence the measure-ment!

• Fill the sample until the ring mark is covered (approximately 0.4 mL)

• Always stir the sample on the prism carefully to allow air bubbles to escape!


Getting started

5. Getting started

5.1 Setting up the instrument

5.1.1 Printer (Setup 0)

If you work without printer you can skip this section and go directly to section 5.1.2. Performthe following steps if you have a GA42 printer to connect:- Make sure that the DIP switch 2 is ON on the GA42 printer.

Press the key

Select "0.Interface". Confirm with .Select "Printer" with the → key. Confirm with .

Select "GA" with the → key. Confirm with .

To choose the format of the printed results press the key and choose between"None", "Short", "GLP" and "Variable" (see section 7 "Report").

Then press the key.

5.1.2 Date and time (Setup 1)

Press the key

Select "1.Date&Time". Confirm with .

Actual date and time are displayed. Press key.

Enter date (the date format is selected in the menu Setup"5.International") and confirm with

Enter the correct time and press .

Printer?GA→

Interface?Printer→

Setup(0-7)? 1 Date&Time

Date & Time:15/04/199811:27

Date DD/MM/YYYY? 20/06/1998

Time? 11:27


Getting started

5.1.3 Enter the lab name (Setup 2)

Press the key.Select "2.Name". Confirm with .

The capital A means that the alphanumerical keyboardis in entry mode for capital letters. Press the key to change the entry mode:

A: capital letters (A, B, C, D, ..)a: small letters (a, b, c, d, ...)1: numbers (0, 1, 2, 3, 4, ...)

Enter the lab name or the instrument name using the alphanumeric keys, e.g. „Quality Lab1”, and confirm with .

The instrument is now ready for calibration and the first measurements.

5.2 Performing the first adjustment (calibration)

After turning on the instrument allow at least 15 minutes for the instrument to warm up beforeperforming the first adjustment.

Note: According to the International Vocabulary of Basic and General Terms in Metrol-ogy from DIN the operation of bringing a measuring instrument into a state ofperformance suitable for its use is called adjustment.The earlier used term calibration should not be used anymore for this purpose assoon as instrument settings are changed or adapted in order to ensure correctmeasurement values.

Press the key and follow the directions on thedisplay.

Open the cover lid and clean the measuring cell (theprism) thoroughly with water and ethanol. Then wipe itdry with a soft tissue, like soft paper towels or washedgauze. Then close the lid and press . Whileadjusting to the air value the display shows shortly:

before switching to

Setup(0-7)? 2 Name

Name? A

Name? 1Quality Lab 1

Clean PrismPress Enter Key

Calibrating25.67°C


Getting started

Method No.? 0Brix

Add water to the measuring cell until the ring mark iscovered (approximately 0.4 mL). After pressing , the following message will be flashing in thedisplay during adjustment to the water value.

When the adjustment is done the display shows thismessage.

The results of the adjustment are printed on the attachedprinter.

The "OLD" value is the measured value of the actualwater with the old adjustment settings.

The "NEW" value is the tabulated value of water as-signed to the actual reading.

These values of the last 10 adjustments) are stored andcan be viewed and printed in the list of adjustments (seechapter 8.4).

When the instrument fails to do the adjustment it willshow an error message.

In such a case clean the prism well, wipe it dry, and repeat the adjustment. If it fails again,then exchange the pure water (make sure it really is of the appropriate quality, i.e. bi-distilledor correctly deionized).

If the adjustment still does not succeed, contact your METTLER TOLEDO service fortechnical assistance.

5.3 Perform a measurement (BRIX, HFCS42 and HFCS55)

Press .

Choose the correct method by using the up and downarrows from the list:

- Method 0: BRIX,- Method 1: Solid (HFCS42),- Method 2: Solid (HFCS55).

Confirm with .

[Calibration]Date : 29/06/1998 11:15

Result : OKTemperature : 27.61 °C

OLD –––> NEWWater 0.00 0.00

Name : Quality Lab 1

----------------

Set WaterPress Enter Key

Calibrating 25.72°C

Calibration 27.61°C OK

Calibration 27.61°C Failed


Getting started

*** R e s u l t ***

Sample No. 02-06

Date : 29/06/1998 12:07Meas.Temp. : 29.81 °CBrix(20.00 °C) : 11.21%


----------------

Now perform for example three measurements with your standard sample.

Press to enter the sample data: sample number and sample ID.

Enter sample no. 02-01: press 2 1 .

Then you can enter your sample ID using the alphanu-meric keys (max. 10 letters) and confirm with .

Add your sample to the measuring cell until the ring mark is covered (approximately 0.4 mL)and stir carefully to remove any air bubbles from the surface of the prism.

Close the cover lid and press (the green key).

The display is flashing during measurement.

When the measurement is finished, the result is dis-played and printed.

Example of a GLP print of such a BRIX measurement.

Sample ID? A Orange J._

0 Brix 29.81°C 11.21%

Measuring 29.85°C 11.23%

Sample No.? [02]- [01]


Sample and Report

6. Sample (Number and ID)

Here you can define your sample identifications like sample number and sample ID.

The sample number is composed of two parts: for example [03]–[01].

The first two-digit number – ranging from 00 to 98 – represents the series number of yourmeasurement series. In the instrument it is called "High Sample No.". If you group yourmeasurements of different sample types by this series number, you can convenientlyprocess your data statistically later on.

The second two-digit number – ranging from 00 to 99 – is automatically increased by one permeasurement.

Additionally you can define a sample ID, for example a sample name or the Lot number.

Press the key.

Enter the sample ID using the alphanumeric keys (max.10 characters including "space", "period" and "hyphen".

7. Report

In the menu you can choose the format of your printout according to thefollowing table.

Short GLP Variable

Name X X XModel/Serial X choiceSample No. X X choiceDate & Time X X choiceSample ID X choiceMethod No. & Name X choiceMeas.Temp. X choiceResult X X choiceMeas. Time X choice

Sample No.? [03]–[01]

Sample ID? A Lot 36-05a


Functions

8. Functions (password protected)

8.1 Data File (Function 0)

This function allows to view and process the measured data. You can either do a recalcula-tion of measured results, statistics on the results or delete single data i.e. mark them so thatthey are not considered in the statistics calculations.

Note: To view stored measured data, use the "Data deletion" function and skip the deletestep.

Select 0 and confirm with .

Now select with the ← and → keys between or and confirm with .

8.1.1 Statistics

The RE20B BRIX meter allows to do a statistical evaluation of your data. You can calculatethe mean value (Mean), the standard deviation (SD) and the relative standard deviation(RSD). The relative standard deviation is the same as the coefficient of variation (CV).

The measured data can be filtered so that useful statistical results can be obtained after adays work. On the first level the method (0 for BRIX, 1 for HFCS42, or 2 for HFCS55) will giveaccess to the respective data only. On the second level the series number (first two-digitnumber of the sample number) can be chosen for which the statistics is to be done.

After selecting and confirmation with , the display asks for the method number (0 forBRIX, 1 for HFCS42, or 2 for HFCS55) for which youwant to perform the statistics. Confirm with .

Next it asks for the High Sample No.: that is the seriesnumber, the first two-digit number of the sample number.Confirm with .

Function(0-6)?0 Data File

Method No.? 0 Brix

High Sample No.? 01

Data File? Statistics→


Functions

Now you select whether the statistics results are to beprinted alone ("Off") or together with a list of all themeasured values ("On"). Confirm with .

The first part of the statistics is now shown on the display.With the down arrow you can switch to the second parti.e. standard deviation and relative standard deviation.

To print the results of the statistics calculation press the key.

To get back to the beginning of the statistics selectionpress the down arrow.

Press to exit the functions.

8.1.2 Data Deletion

This function allows to exclude single measured values from the statistics calculation bymarking them with an asterisk.

Select data deletion with the ← and → keys and confirmwith .

Now enter one of the numbers of the given range (forexample 00) and press .

You can flip through the list of the selected measurementusing the ← and → keys.

Pressing the key will turn on and off anasterisk on the selected measurement number.

Data File? Data Deletion→

Deletion No. (00-06)?06

01-05 Orange J.00 11.38%

01-05 Orange J.00* 11.38%

Date : 29/06/1998 17:29Sample No.(High) : 01Method No. : 0(Brix)

Results: 4Mean : 11.21SD : 0.06RSD : 0.54


----------------

Data Print? Off→

Results: 4Mean : 11.21%

SD : 0.06%RSD : 0.54%


Functions

Now you can resume the statistics calculation again and then print the results without themarked measurements. If you selected the data print "On" the excluded measurements willbe printed with an asterisk before the sample number.

8.2 Set check (Function 1)

In this function you can set up the substances - name, rated value and allowed tolerances -you want to use as standard check samples either for the daily or the periodic check.

Select function 1 - Set Check - and confirm with .

With the ← and → keys select either "Daily" or "Periodic"and confirm with .

8.2.1 Set Daily Check

This check is used mainly to control the working condition of the instrument. Is the instrumentreally clean and dry? Did the previous operator really clean the cell after measuring hissample?Pressing the check key will start a periodic check only when such a test is due according tothe settings in section 8.3. When no periodic check is due it will start a daily check.

Normally deionized or bi-distilled water is used for this purpose. Of course any other solutioncan be used that suites the purpose i.e. is readily and in abundance available as well as hasa stable and well known composition.

Enter the name of the check solution (max. 10 charac-ters) using the alphanumeric keys.

Enter the rated value of the check solution and confirmwith .

Enter the allowed tolerances for this solution and confirmwith .

The results of this daily check are not stored in the instrument. They are just meant to checkwhether the instrument is really ready for the next measurement.

Standard? A Water

Ref.Value? 0.00%

Tolerance? 0.15%

Set Check? Daily→


Functions

8.2.2 Set Periodic Check

This check is used mainly to verify whether a new adjustment of the instrument is necessaryor not. Every adjustment of the instrument means that the instrument settings are changed.This can be dangerous if it is not done correctly because all the measurements afterwardswill be wrong.Pressing the check key will always activate a daily check, unless a periodic check is due (seealso section 10.6). When no periodic check is due it will start a daily check.

So instead of actually performing frequent adjustments we suggest to perform frequentchecks with an exactly known standard solution. As long as this periodic check is donesuccessfully, there is no need to adjust the instrument. The results of period checks arestored automatically in the instrument.

Should the periodic check fail, the operator should carefully clean and dry the measuring celland then repeat the periodic check.

If it still fails, then the instrument should be adjusted again: press the key and followthe instructions of the instrument.

If the periodic check fails too often - like every second or third time - then you should contactyour METTLER TOLEDO office for servicing and closer support.

A standard solution can be a commercially available standard of well-defined accuracy (acertified reference standard) or a standard that is prepared in-house strictly according to anSOP.

For example a solution of 10.00% sucrose in doubly distilled water - i.e. weigh 10.00 gsucrose into a volumetric flask and fill up with doubly distilled water to exactly 100.00 g -could be used for this purpose.

Select "Periodic" under function 1 (with the key) and confirm with .

Enter the name of the check solution (max. 10 charac-ters) using the alphanumeric keys.

Enter the rated value of the check solution and confirmwith .

Enter the tolerances you want to allow for this solutionand confirm with .

Standard? A 10 Brix

Ref.Value? 10.00%

Tolerance? 0.06%


Functions

8.3 Periodic Check (Function 2)

This function is used to set the intervals of the periodic check. This function is also used todisplay and print the last check data stored in the instrument.

The display will show the due date for the next periodiccheck. This due date is calculated automatically by theinstrument according to following settings. Confirm with.

Select the periodic check (Check Alarm to be "On" or"Off", and confirm with .If "On" is selected, the instrument will give one of thefollowing messages when it is turned on:"X Days To Check" as a remainder, "Check Day" on thedue date, and "Check Day Over!" on the following days.Each of these displays will return to the "Ready" displayafter a while.If "Off" is selected, the instrument will not remind you tocheck.

Enter the check interval (in days) and confirm with .Note: Enter 0 Day to force a periodic check on today's

date. This will especially be required if the peri-odic check has failed, in order to perform it again.

Select "Yes" to display the list of the last 10 checksperformed. The whole list can be printed by pressing the key.

When "Yes" is selected and confirmed with ,the last check result is displayed. You can switch throughthe other check results using the ← and → keys.The whole list can be printed pressing the key.

If there are no such data (none performed yet or datacleared previously), this message starts flashing. Press-ing any key will return the screen to "Function(0-6)?".

The results of such a periodic check are automatically stored in the instrument. You can viewthe last 10 checks performed as described above.

Check Interval? _ 7Day

01; 10 Brix OK29/06 10.00%

Next Check Date: 06/07/1998

Check Alarm? On→

Data not exist.Press Any Key!

Show Check List? Yes→


Functions

Note: Once the periodic check has been performed the CHECK key will automaticallyswitch to the daily check. In order to repeat a periodic check, set the Check Intervalto 0 Day to force a periodic check on today's date. This will especially be required ifthe periodic check has failed, in order to perform it again.

8.4 Periodic adjustment, resp. calibration (Function 3)

This function is used to set the intervals of the periodic adjustment (calibration). This functionis also used to display and print the last adjustment data stored in the instrument.The instrument has to be adjusted from time to time. You can either choose the timeaccording to your special needs i.e. perform it when the periodic check fails for example twotimes successively, or you can define a certain time period after which the instrument willremind you to repeat the adjustment.

The results of these adjustments will automatically be stored by the instrument. You can viewat any time the last 10 adjustments performed and also print out the list for documentationpurposes as described below.

Select function 3 "Periodic Calib." and confirm with .

The display will show the due date for the next periodicadjustment. This due date is calculated automatically bythe instrument according to following settings. Confirmwith .Select the periodic adjustment to be "On" or "Off", andconfirm with . If "On" is selected, the instru-ment will give one of the following messages when it isturned on:"X Days To Calib" as a remainder, "Calib. Day" on thedue date, and "Calib. Day Over!" on the following days.Each of these displays will return to the "Ready" displayafter a while.

Enter the periodic adjustment interval (in days) and con-firm with .Note: Enter 0 Day to force a periodic adjustment on

today's date.

Select "Yes" or "No" with the → key whether or not the listof the last 10 adjustments performed is to be displayed.The whole list can be printed by pressing the key.

Next Calib.Date: 06/07/1998

Calib.Alarm? On→

Calib.Interval? _ 7Day

Show Calib.List? Yes→


Functions

When "Yes" is selected and confirmed with ,the last adjustment data is displayed. You can switchthrough the other adjustment data using the ← and →keys.

If there are no such data (none performed yet or datacleared previously), this message starts flashing. Press-ing any key will return the screen to "Function(0-6)?".

8.5 Memory Clear (Function 4)

This function is used to reset all parameters to default (factory setting), for instance toinitialize the memory after a serious malfunction of the instrument.

You can also selectively reset single records like the adjustment data (Calib. data), the checkrecords, the sample files or the method parameters.

Press 4 and confirm with .

Select the desired option with the ← and → keys:"Measured Data", "Sample File", "Periodic Check", "Peri-odic Calib.", "Method Para.", "All Parameter", and con-firm your choice with .

Select "Yes" to confirm your choice again and press.

The chosen data or parameters are now deleted and the respective factory settings areactive again.

8.6 Wait Time (Function 5)

If the sample temperature is too far from the prism temperature, a measuring error is likely tooccur because of a sharp temperature change when the sample is applied to the prismsurface. To prevent this problem you can define a wait time in seconds. When you press the internal clock of the instrument first counts back this time before actually startingthe measurement. Thus the sample has time to adapt roughly to the prism temperature.

Press 5 .

Enter the wait time (in seconds) and confirm with.

01;29/06/1998 OK 0.00% → 0.00%

Data not exist.Press Any Key!

Memory Clear? Measured Data→

Clear Execute? Yes→

Function(0-6)?5 Wait Time

Wait Time? _ 10s


Functions

8.7 Decimals (Function 6)

Here you can select the number of decimals you want to show in the results of yourmeasurements.

Select 6 and confirm with .

Enter the number of decimals for the result display:choose between 0, 1 or 2. Confirm with .

Note: Since the RE20B BRIX meter in fact has only one method that allows three differentresult calculations – i.e. BRIX, HFCS42 and HFCS55 – the wait time as well as thedecimals in result display will be valid for all measurement that are performed afterdefining it. When a different wait time is needed, you have to set it up anew.

Function(0-6)?6 Decimals

Decimals (0-2)? 2


Setup

9. Setup (password protected)

9.1 Interface (Setup 0)

This option is used to setup the RS-232C serial interface and the serial printer.

Press the key.

Select "0.Interface". Confirm with .

Select "Printer" with the -> key in order to setup theprinter or "RS-232C" to setup the serial interface

9.1.1 Printer setup

We recommend to select the GA42 printer from METTLER TOLEDO. Make sure that the DIPswitch 2 is ON on the GA42 printer (see operating instructions of the GA42).

Following printers are available:GA- : for GA42 and SPRINTER printer from

METTLER TOLEDO.Other: for all serial printers. Selection of:

- Baud rate (300, 600, 1200, 2400,....)- Parity (none, even, odd)- Stop bits (1, 2)- Data bits (7, 8)

These parameters have to be set according tothe specifications of your printer.The bold settings are active for the GA42 printer.IDP- : not usedDP- : not used

Setup(0-7)?0 Interface

Interface? Printer→

Printer?GA→


Setup

9.1.2 RS-232C Interface setup

This option is used to set the RS-232C interface for connecting a computer. Make sure thatthe computer is set up with the same values.

Select "RS-232C" with the → key. Confirm with .

Select the following values according to your computersetup.

9.2 Date and Time (Setup 1)

This option is used to enter the correct date and time.

Press the key.

Select "1.Date&Time". Confirm with .

Actual date and time are displayed. Press key.

Enter date (the date format is selected in the menu Setup„5.International”) and confirm with .

Enter the correct time and press .

Interface? RS-232C→

Baud Rate?1200→

Parity?None→

Setup(0-7)? 1 Date&Time

Date&Time?1998/06/30 14:56

Date DD/MM/YYYY?20/06/1998

Time? 11:27


Setup

9.3 Name (Setup 2)

This option is used to enter the laboratory (or company or operator) name.

Press the key.Select "2.Name". Confirm with .

The capital A means that the alphanumerical keyboardis in entry mode for capital letters. Press the key to change the entry mode:

A: capital letters (A, B, C, D, ..)a: small letters (a, b, c, d, ...)1: numbers (0, 1, 2, 3, 4, ...)

9.4 Serial/Version number (Setup 3)

This option is used to identify the software version and the serial number of your instrumentwithout having switch off the instrument.

- Press the key.Select "3.Serial/Version" .

Press the key. The serial number of yourinstrument as well as the software version are displayed.

9.5 LCD Contrast (Setup 4)

This option is used to setup the contrast of the LCD display in your instrument.

Press the key.

Select "4.LCD Contrast".Confirm with .

Press the corresponding number key on the alphanumer-ical keyboard (0:low, 3:normal, 6:high)

Name? A

Name? 1Quality Lab 1

Setup(0-7)? 2 Name

Setup(0-7)? 3 Serial/Version

Serial :xxxx xxxxVersion: x.xxx

Setup(0-7)? 4 LCD Contrast

LCD Contrast? 4Low:0 6:High


Setup

9.6 International (Setup 5)

This option is used to select the date format and the unit for the temperature (°C or °F).

Press the key.

Select "5.International".Confirm with .

Select "Date" or "Temp.Unit" with the → key.Confirm with .

9.6.1 Setup date format

Select "Date" with the → key. Confirm with .

Select your date format with the → key.YYYY: YearMM : MonthDD : Day

9.6.2 Setup temperature unit

Select "Temp.Unit" with the → key. Confirm with .

Select your temperature unit with the → key.°C : degree Celsius°F : degree Fahrenheit

9.7 Lock with password (Setup 6)

Press the key.

Select "6.Lock".Confirm with .

Select "On" with the → key.Confirm with .

Setup(0-7)? 5 International

International?Date→

International? Date→

Date? YYYY/MM/DD→

International? Temp.Unit→

Temp.Unit? °C→

Setup(0-7)? 6 Lock

Lock? On→


Setup

Enter your password. Make sure to keep it in a safe placein case you would forget it.

Enter your password a second time to confirm the correctspelling.

In case you would have forgotten your password you will need to call the METTLERTOLEDO service.

9.8 Beep (Setup 7)

Press the key.

Select "7.Beep".Confirm with .

Select "On" with the → key.Confirm with .

Enter your beep selection:1: long and fast2: long and slow3: short and fast4: short and slow

Setup(0-7)? 7 Beep

Beep? On→

Beep Type(1-4)? 4

Password? ********

Password? ********


Error messages and malfunctions

10. Error messages and malfunctions

Messages appear in the display for several errors and malfunctions; causes and correctivemeasures for these and other faults are listed below.

Cause

You have not cleaned the prismfor a zero point calibration

You have no sample in themeasuring cell and havepressed the Meas. key

Key is locked! You have, e.g.pressed the Method key duringa measurement

The method is protected! Youhave pressed the Meas. Para.,Calcu. Para. or Print Para. key

Value below or above measure-ment range for this sample

The temperature sensor of thethermostat control is faulty

The LED light source is faulty

Possible cause

Cable not plugged in properly,fuse blown

Internal battery dead

Prism faulty

Display contrast is set to mini-mum or maximum

Measure

First clean the prism and thencalibrate

First add the sample

(Press Reset, if you wish toabort the measurement)

Remove protection as appropri-ate (see Section 9.7)

Switch the instrument off andcall METTLER TOLEDO service


Measure

Check power cable, on/off switchand fuses



Change contrast setting (seeSection 9.5)

Error message

Prism not clean

No sample

Busy !

Protected !

Out of range

Temp Error

Lamp NG

Malfunction

Instrument can notbe switched on

Stored datahave been lost(e.g. date)

Measurements ofsame sample notreproducible

Blank display


Standard and optional equipment

11. Standard and optional equipment

11.1 Standard equipment

Order No.

One BRIX Refractometer RE20BOne set of Operating Instructions 51709840One power cable in accordance with your order

11.2 Optional equipment

GA42 printer:- Alphanumerical printer (serial) GA42- Set of paper rolls (5 pcs) 00072456- Ribbon catridge (black) 00065975- Connection cable (not included) 51190362

PC software (for Windows 95 & 98):- Data transfer software to EXCEL (version 7.0 or later) 51324100- Connection cable to computer 51190362


MemoCard RE20B (Short Instructions)

Sample No, Sample ID

Select print formatoffshortGLPvariable

Method selection0: Brix1: HFCS422: HFCS55

Display selection

Print message or parameter

Start measurement

Backspace (erase)

Clear entry (2x to clear name)

Escape

Return to main display

Report

Sample Function

Check

Setup

Calib.

BS

Method

Display

Print

Function selection0. Data file1. Set check

(name, value, tolerance)2. Periodic check

(check interval)(show check list)

3. Periodic calibration(calibration interval)(show calibration list)

4. Memory clear5. Wait time6. Decimals

Setup selection0. Interface

(Printer, RS-232)1. Date & Time2. Name3. Serial/Version No.4. LCD contrast5. International

(date format)(°C or °F)

6. Lock7. Beep

Run instrument check (*)Periodic check (on check date)Daily check (all other dates)

Perform an adjustment

Clear

Esc.

Reset

Measure

(*) Note: Once the periodic check has been performed the CHECK key will automatically switch to the dailycheck. In order to perform a periodic check again, set check interval (Function 2) to 0 Day to forcea periodic check on today's date. This will especially be required if the periodic check has failed, inorder to perform it again.


Table

Annex 1: BRIX Table

The stored conversion tables in the instrument are based on: Adjusted refractometer valuesfor the concentration of sucrose in water at 20 °C (λ = 589.3 nm). Based on the 16th sessionof the International Commission of Uniform Methods for Sugar Analysis (ICUMSA), 1974.

The temperature correction tables used in the instrument are based on the InternationalRecommendation OIML R 108 (Edition 1993, E). See Annex 2.

BRIX table

Brix Refractive Brix Refractive Brix Refractive% Index nD % Index nD % Index nD

0 1.332991 1.334422 1.335863 1.337324 1.338795 1.340266 1.341757 1.343258 1.344769 1.34629

10 1.3478211 1.3493712 1.3509313 1.3525014 1.3540815 1.3556816 1.3572917 1.3589118 1.3605419 1.3621820 1.3638421 1.3655122 1.3672023 1.3688924 1.3706025 1.3723326 1.3740627 1.3758228 1.3775829 1.37936

30 1.3811531 1.3829632 1.3847833 1.3866134 1.3884635 1.3903236 1.3922037 1.3940938 1.3960039 1.3979240 1.3998641 1.4018142 1.4037843 1.4057644 1.4077645 1.4097846 1.4118147 1.4138548 1.4159249 1.4179950 1.4200951 1.4222052 1.4243253 1.4264754 1.4286255 1.4308056 1.4329957 1.4352058 1.4374359 1.43967

60 1.4419361 1.4442062 1.4465063 1.4488164 1.4511365 1.4534866 1.4558467 1.4582268 1.4606169 1.4630370 1.4654671 1.4679272 1.4703773 1.4728574 1.4753575 1.4778776 1.4804077 1.4829578 1.4855279 1.4881080 1.4907181 1.4933382 1.4959783 1.4986284 1.5012985 1.50398


Table

°BRIXTemp °C 0 5 10 15 20 25 30 35 40

to be substracted from the °BRIX value

10.00 0.52 0.56 0.59 0.61 0.64 0.67 0.69 0.71 0.7211.00 0.48 0.51 0.54 0.55 0.58 0.61 0.63 0.65 0.6512.00 0.44 0.47 0.49 0.50 0.52 0.55 0.57 0.58 0.5813.00 0.39 0.42 0.43 0.44 0.46 0.49 0.50 0.51 0.5114.00 0.35 0.37 0.38 0.39 0.40 0.42 0.43 0.44 0.44

15.00 0.29 0.31 0.32 0.33 0.34 0.35 0.36 0.37 0.3716.00 0.24 0.25 0.26 0.27 0.28 0.28 0.29 0.30 0.3017.00 0.18 0.19 0.20 0.20 0.21 0.21 0.22 0.22 0.2318.00 0.12 0.13 0.13 0.14 0.14 0.14 0.15 0.15 0.1519.00 0.06 0.06 0.07 0.07 0.07 0.07 0.07 0.08 0.08

°BRIXTemp °C 0 5 10 15 20 25 30 35 40

to be added to the °BRIX value

21.00 0.06 0.07 0.07 0.07 0.07 0.07 0.08 0.08 0.0822.00 0.13 0.14 0.14 0.14 0.14 0.15 0.15 0.16 0.1623.00 0.20 0.21 0.21 0.22 0.22 0.23 0.23 0.23 0.2324.00 0.27 0.28 0.29 0.29 0.30 0.30 0.31 0.31 0.3125.00 0.34 0.35 0.36 0.37 0.38 0.38 0.39 0.39 0.40

26.00 0.42 0.43 0.44 0.45 0.46 0.46 0.47 0.47 0.4827.00 0.50 0.51 0.52 0.53 0.54 0.55 0.55 0.56 0.5628.00 0.58 0.59 0.60 0.61 0.62 0.63 0.64 0.64 0.6429.00 0.66 0.67 0.68 0.69 0.70 0.71 0.72 0.73 0.7330.00 0.74 0.75 0.77 0.78 0.79 0.80 0.81 0.81 0.81

Annex 2: Temperature corrections for BRIX refractometer values


Table

°BRIXTemp °C 45 50 55 60 65 70 75 80 85

to be substracted from the °BRIX value

10.00 0.74 0.74 0.74 0.75 0.76 0.77 - - -11.00 0.67 0.67 0.67 0.68 0.68 0.69 - - -12.00 0.60 0.60 0.60 0.60 0.61 0.61 - - -13.00 0.53 0.53 0.53 0.53 0.53 0.53 - - -14.00 0.45 0.45 0.45 0.45 0.45 0.46 - - -

15.00 0.38 0.38 0.38 0.38 0.38 0.38 0.38 0.37 0.3716.00 0.30 0.31 0.31 0.31 0.31 0.31 0.30 0.30 0.3017.00 0.23 0.23 0.23 0.23 0.23 0.23 0.23 0.23 0.2218.00 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.1519.00 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08

°BRIXTemp °C 45 50 55 60 65 70 75 80 85

to be added to the °BRIX value

21.00 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.0722.00 0.16 0.16 0.16 0.16 0.16 0.15 0.15 0.15 0.1523.00 0.24 0.24 0.24 0.24 0.23 0.23 0.23 0.23 0.2224.00 0.32 0.32 0.32 0.32 0.31 0.31 0.31 0.30 0.3025.00 0.40 0.40 0.40 0.40 0.39 0.39 0.39 0.38 0.37

26.00 0.48 0.48 0.48 0.48 0.47 0.47 0.46 0.46 0.4527.00 0.56 0.56 0.56 0.56 0.55 0.55 0.54 0.53 0.5228.00 0.65 0.65 0.64 0.64 0.64 0.63 0.62 0.61 0.6029.00 0.73 0.73 0.73 0.72 0.72 0.71 0.70 0.69 0.6830.00 0.82 0.81 0.81 0.81 0.80 0.79 0.78 0.77 0.75


Table

Specifications

Type and model name RE20B BRIX Refractometer

Measuring method optical detection of critical angle with Na-D line (589.3 nm)

Measuring range BRIX 0.00 to 100.00 %

Precision BRIX 0.03 %

Repeatability BRIX 0.01 %

Resolution BRIX 0.01 %

Temperature range T 15 to 40 °C

Temperature precision T 0.05 °C

Temperature compensation rangeBRIX 15 to 40 °C

Sample required min. 0.2 mL, 0.4 mL to cover the ring mark

Typical measuring time ~ 5 sec (depending on sample)

Display LCD (Liquid crystal display), 2 line display

Ambient condition 1) Temperature: 5 ~ 35 °C2) Humidity: below 85 % RH (no condensation)

Power source AC 100-240 V, 50/60 Hz

Power consumption 20 W

Dimension 270 mm (W) x 400 mm (D) x 225 mm (H)

Weight 6 kg

FCC Rules and Radio Interference Regulations

This equipment has been tested and found to comply with the limits for a Class A digital device, pursuant toboth Part 15 of the FCC Rules and the radio interference regulations of the Canadian Department ofCommunications. These limits are designed to provide reasonable protection against harmful interferencewhen the equipment is operated in a commercial environment. This equipment generates, uses and canradiate radio frequency energy and, if not installed and used in accordance with the instruction manual, maycause harmful interference to radio communications. Operation of this equipment in a residential area is like tocause harmful interference in which case the user will be required to correct the interference at his ownexpense.

To protect your METTLER TOLEDO product’s future:METTLER TOLEDO Service assures the quality, measuring accuracy andpreservation of value of all METTLER TOLEDO products for years to come.Please send for full details about our attractive terms of service.Thank you.

© Mettler-Toledo GmbH 2000 ME-51709840 Printed in Switzerland 00/01/2.12

Printed on 100% chlorine-free paper, for the sake of our environment.

Mettler-Toledo GmbH, Analytical, Sonnenbergstrasse 74, CH-8603 Schwerzenbach, Tel. (01) 806 77 11, Fax (01) 806 73 50,Internet: http://www.mt.com

Subject to technical changes and to the availabilityof the accessories supplied with the instruments.*P51709840*

Contents PageTitle Page1. Introduction 2. Safety measures 3. BRIX, HFCS and Refractive Index 3.1 Definition of refractive index 3.2 Definition of BRIX (%) 3.3 Definition of HFCS42 and HFCS55 (Inverted sugar) 3.4 Measurement principle

4. The instrument 4.1 General overview 4.2 Keyboard 4.3 Display 4.4 Measures for correct measurements

5. Getting started 5.1 Setting up the instrument 5.2 Performing the first adjustment (calibration) 5.3 Perform a measurement (BRIX, HFCS42 and HFCS55)

6. Sample (Number and ID) 7. Report 8. Functions (password protected) 8.1 Data File (Function 0) 8.2 Set check (Function 1) 8.3 Periodic Check (Function 2) 8.4 Periodic adjustment, resp. calibration (Function 3) 8.5 Memory Clear (Function 4) 8.6 Wait Time (Function 5) 8.7 Decimals (Function 6)

9. Setup (password protected) 9.1 Interface (Setup 0) 9.2 Date and Time (Setup 1) 9.3 Name (Setup 2) 9.4 Serial/Version number (Setup 3) 9.5 LCD Contrast (Setup 4) 9.6 International (Setup 5) 9.7 Lock with password (Setup 6) 9.8 Beep (Setup 7)

10. Error messages and malfunctions 11. Standard and optional equipment 11.1 Standard equipment 11.2 Optional equipment

Annex 1: BRIX Table Annex 2: Temperature corrections for °BRIX refractometer values Specifications

Documents

RE20B 1.02 e · Inverted sugar concentration can be converted from the refractive index of the inverted sugar solution measured at 20 °C (nD 20). The RE20B stores conversion tables