Non Contact Infrared Thermometers

for the Glass Industry

T H E I N F R A R E D P R O S

2

The Glass Industry

Glass manufacturing was one of the first industries to use non-contact

temperature measurement. Many of today’s non-contact infrared sensor

designs evolved directly from the needs and demands of the diverse, and

many times harsh processes entailed in the making of glass products in

their various forms.

Mikron Infrared Inc. has been closely engaged in the creation and design

evolution of non-contact temperature sensors for the Glass Industry for

over 35 years. Mikron’s sensor specifications and protective housing

designs are in direct response to the special needs of the Industry,

and have progressively taken advantage of the dramatic strides in optics,

electronics and detector technology.

Today, Mikron infrared thermometers are to be found globally, in all

segments of both primary and secondary glass manufacturing:

• Automotive and Architectural • Decorative and Tableware

• Container and Fiber • Optical Waveguide Production

• Lamp and Lighting • Tempering, Laminating and Forming

The company now offers the world’s most comprehensive, single-source

array of fixed mounted and portable non-contact infrared thermometers,

along with hand held and fixed thermal imaging systems. In support of its

sensors, Mikron also has a range of calibration standards and services that

provide traceability, referenced to national standards.

The following pages will provide you with an overview of Mikron products for

the Glass industry, and of applications that have been successfully engi-

neered. More detailed product information, or the location of your Mikron

representative, can be found on our website at www.mikroninfrared.com.

Glass gob distributor

IR Fiber Optic Sensor installed nearglass gob distribution (exit of forehearth)

Non-contact IR fiber optic sensors located on top of forehearth

Melt tank/forehearth

Glass bottle forming lineIR Sensor measuring temperature of glass gob

3

Float Glass Process Applications

Float Glass

Glass Cutting Area

After the melt tank (1), the first points of measurement

on Float Glass lines are in the Canal Area (2) followed

by the Tin Bath (3), which requires multiple measure-

ments to profile the glass. The Canal Area uses a

pyrometer with a 1µ spectral response. Generally a

fiber optic sensor is preferred. Sensors in the 5µ spec-

tral response region are used here to sense the glass

surface temperature.

In the Annealing Lehr (4), again sensors in the 5µ

region are installed to sense near the edge and the

center of the glass ribbon in each of the annealing

zones. In the Cooling Zones near the end of the Lehr,

and to determine the correct ribbon temperature in the

glass cutting location (5), more economical sensors

with 8-14µ spectral response can be used.

Melting & RefiningThe melt tank (1) and refiner area temperature meas-

urement applications are common to many segments

of the Industry. The measurement locations are: The

furnace crown, the bridgewall, the burner port block,

and the molten glass in the regenerator melt tank furnace.

Sensors in the region of 1µ (micron) with and without

fiber optics are used in this area. Due to the extreme

environmental temperatures, water cooling is neces-

sary for non-fiber optic models. Fiber optic models are

used when water cooling is not desirable. Single wave-

length (1 color) pyrometers are used throughout the

Float Glass Process.

Bending, Tempering and SaggingIn the bending, tempering and sagging applications

associated with the secondary processing of flat glass,

sensors in the region of 5µ are used to measure glass

surface temperature.

Other spectral responses have been used to measure

temperatures just below the glass surface as a means

of preventing “skin effect” stress patterns.

Melt Tank

Tin Bath

Annealing Lehr

Lehr Exit

4

5

3

12 Canal Area

4

Container & Fiber Glass Process Applications

Melt Tank

DistributionArea

ParisonForming Area

Melt Tank

Container LinesThe end point of measurement on a container forehearth is theGob (4). Gob temperature measurement requires a sensor with1µ spectral response to sense beneath the gob surface in orderto avoid surface cooling effects. For very small gobs, less than25mm (1.0”) dia., it is necessary to sight up into the orifice toavoid “seeing” partially through the glass. Generally, IR sensorswith fiber optic, or non-fiber optic versions with through-lenssighting or video are used in this location.

Single color with short wavelength or 2 Color sensors withthrough-lens sighting are used for the Plunger (5) measurementto eliminate inaccuracies due to variable surface emissivity.Typically sensors with a speed of response of 10 milliseconds orless are used for gob or plunger temperature measurements.

In the Parison Forming area, Mold temperature (6) is measuredwith a fixed sensor system and/or a portable M90QFOThermometer. The M90QFO employs a stainless steel fiber optic“wand” terminating in a “cupped” tip. This allows an operator tomomentarily touch the mold surface and record up to 40 read-ings that can be downloaded and analyzed on a computer. Ashort wavelength spectral response minimizes emissivity varia-tions due to mold age or doping, and in the case of theM90QFO, the cupped tip eliminates reflected energy from hotglass or other molds in the vicinity. Additionally, fixed processsensors with a spectral response of 3.9µ or fiber optic modelswith1.8µ are used to see through clean flames impinging on themolds.

Container Glass and Fiber GlassContainer and fiber glass lines have common features in thatthey both have a melt tank refiner area and a Distributor with several Forehearths. Normally, fiber glass forehearths are longerand therefore have more zones than the container line equivalent. In the Distribution Area (2) IR sensors in the region of1µ wavelength are used to measure just below the surface of theglass at one or more points. Due to extremely hot environmentalconditions, fiber optic models are preferred.

In the Forehearth (3), again fiber optic sensors with 1µ spectral

response are used to sense each zone temperature, and meas-ure approximately 25mm (1”) into the glass. On some fore-hearths, zone temperature is combined with an additional IRthermometer, sighted into a molybdenum tube through the bot-tom of the forehearth, just before the orifice, to detect tempera-ture gradients in the glass.

At the end of the glass conditioning phase in the forehearth, thecontainer and fiber glass processes differ.

Fiber GlassIn fiber glass production, the last point of measurement of theforehearth, is at the Platinum Bushing (4). A variety of techniqueshave been used in this final production stage to ensure that correct temperature and temperature distribution across thebushing is maintained. This insures that the holes in the bottomof the Platinum Bushing remain open and unobstructed, allowing

the molten glass to flow. For this measurement, portable or fixed systems with narrow-band, short wavelength spectralresponse or two color thermometers are used. All non-contactinfrared thermometers avoid the errors attributable to electrical orelectro-magnetic interference that complicate thermocouplemeasurements.

DistributionArea

1

3

4

UPWARD VIEW OF PLATINUM BUSHING

1

2

2

Forehearth3

Platinum Bushing4

Forehearth

Gob 5Plunger

Blank / MoldTemperature6

5

Lamp & Lighting Process Applications

Like Container and Fiber Glass production, Lamp and Lighting only differs in the forming and

secondary manufacturing stages. Depending on the glass materials under process such as soda

lime, lead glass or borosilicate (quartz) temperatures vary, ranging from approximately 500°C to

2200°C respectively. Mikron’s Line of IR Sensors at 5 micron spectral response are used to

measure glass/quartz surface temperature, whether it is viewed directly or through clean flames.

In the case where the glass is luminous, (molten glass), an IR Sensor with a 1 micron spectral

response should be used.

Mikron’s non-contact infrared temperature sensors are ideal for monitoring and control of critical processes in the manufacture of

incandescent bulbs, fluorescent tubes (mercury/sodium vapor) metal halide and high intensity discharge lamps. Mikron has a

variety of products available for lamp/bulb flame sealing, bending, annealing and forming applications including the models M67S

with through lens sighting, MI-N5/5+, with laser sighting and the M67SV which has video monitoring capability. For checking filament

temperature choose from the M770S a fast, highly accurate Digital 2-color sensor with variable focussing optics or M770SV which

incorporates video capability. The fiber optic model M780 is used in harsh and confined areas. In addition single color fiber optic

sensors can be used to measure pinch die temperature, to reduce breakage in automotive lamp glass applications.In addition, the

IR Sensor’s speed of response should be considered due to the very high speed nature of the Lamp/Lighting Glass Process.

1

2

3

45 Sealing Area

Tube Carousel

Cutting/Coating Line

Melt Tank(Not Shown)

Forehearth

Accurate automotive lamp glass temperature measurementprevents seal failure and Pinch Die breakage due to low glass temperature

Mikron Infrared Sensors areused to measure glass to leadglass seal on fluorescent tubes.

Temperature measurement isused to control and prevent acold seal, rod voids, cracking,and shrinkage.

Glass to Glass, Glass to Metal, Sealing Applications

Fluorescent tube Glass to LeadGlass Sealing Process – TubeCarousel

Vello/Danner Process Area3 measuring points

1) Glass Temp coming out of the orifice

2) Glass on Sleeve3) Glass on nose

123

6

Mikron IR Products for Glass Industry Applications

Materials Measurement Points Mikron Models

Non-Molten Glass Surface

M67S(E)MI-N5/5MI-N5/5+MI-N5/5-M+MI-N5/5-H+

µ

5Tin Bath

LehrLampsBulbs

Molten Glass or Refractory

Melt Temp.Canal Area

Distribution AreaForehearth

GOB

M67S(H)M190HMI-S5MI-S5-TVMI-S10

MI-S200MI-S300

Fiber Optic Models

M68M668M680(H)MI-S5-LO-GLMI-S50-LO-GL

µ

1

Metal Surface

BlanksMolds

PlungersPinch Die

M67S(H),(Q),(D)M190(H),(Q)MI-S5MI-S5-TVMI-GA5MI-GA5-TVMI-S10MI-GA10

MI-GA10MI-GA140MI-S140MI-P140MI-S200MI-GA200MI-S300MI-GA300

µ

1

MI-N200/5MI-N300/5

Tungsten Surface

M770SM770SV (Video Output)

M9103 (High Resolution Thermal Imaging System)

M9104

Fiber Optic Models

M68M668M680(H) (IN)MI-S5-LOMI-S50-LO-GLMI-SQ10-LOMI-GAQ10-LO

Portable

M90QFO

Filament

Portable

M90H

Portable

M90(E)M120GL

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Mikron Products for Glass Industry Applications

MI-S300 MI-GA300Good value, small, fast(10ms), medium/high tem-perature, 2-wire pyrometerswith fixed focus, adjustableemissivity and LED aiming,easy installation.

MI-S200 MI-GA200Fast (20ms), medium/high temperature, digital pyrome-ters with analog output, 2-wire design, maximum value storage, programmablemeasuring range, LED aiming.

MI-S5 MI-GA5Very fast (2ms) digital pyrome-ters with analog output anddigital interface. Maximumvalue storage, adjustablemeasuring range, laser aimingor through-the-lens sighting or integrated TV camera.

MI-N5/5 MI-N5/5+Glass surface measurement,digital pyrometers with analogand digital outputs, 5.14µmspectral response, 80msresponse time, laser aiming.

MI-N5/5-M+ MI-N5/5-H+Glass surface measurement, highspeed version of MI-N5/5+ with30ms and 10ms response times,laser aiming, spectral range 5.14µm.

MI-S50 LO/GL MI-S5 LO/GLFiber optic pyrometers for measurement of molten glass for forehearth, feeder and gobs.Adjustable measuring ranges, 2-wire design, analog output(service interface).Digital with adjustable meas-uring ranges with 250ms and2ms respectively

M67S E, D, HDiversified industrially hardenedpyrometer with precision uprightthrough lens sighting, focusableoptics, adjustable emissivity andeasy 2-wire installation with 4-20mA analog output. Speed ofresponse 100ms/100ms/10ms.

M190 H, QDigital pyrometer with precisionfocusable optics, 0.1°C resolution,analog outputs, and adjustableemissivity. Designed for precisionprocess applications. 50ms speedof response.

M90 HHigh accuracy hand-held forspot checks or tripod mountedfor rapid and dependable datagathering. Variable focus opticalsystem allows for precision pinpointing of small targets.200ms speed of response.

M90QFOPortable, specifically designed for rapid, easy and convenientmeasurement of mold surface temperatures between 300° and1500°C. This instrument avoidserrors caused by mold surfaceemissivity and reflected energy.100ms speed of response.

M68, M668Fiber optic models for non-con-tact temperature measurementof inaccessible locations wheredirect sighting is impossible orwhere exceptionally high ambi-ent temperatures exist or EMI orRF interference is a problem.Speed of response 10ms and50ms respectively.

M680 HMulti-channel ultra precision fiberoptic system. Wide range digitalpyrometer with precision optics.Digital output, optional 4-20 mAanalog output, long stainless steelsheathed fiber optic cable lengthsand 50ms response speed.

MI-GA140 MI-S140Highly accurate, fully digital fastpyrometer for temperaturesbetween 300 and 3300°C.Response times <1ms optional500µs, thru-lens viewfinder or lasertargeting. Built-in digital display withtemperature indication.

MI-N300/5Glass surface measurement,2-wire design, 5.14µm spec-tral response and 100msspeed of response.

MI-N200/5Glass surface measurement,(2-wire loop powered design)with service interface.Programmable measuringrange, 5.14µm spectralresponse and 120ms speed of response.

M770SDigital 2/color pyrometer with precision focusable optics,adjustable slope, alarm relay andtemperature display for temperaturerange 1112°F to 6332°F. Powerfulsoftware for process diagnostics. 4-20mA and RS485 outputs.

ISO 9001

Mikron Infrared, Inc., Headquarters16 Thornton RoadOakland, NJ 07436 USATel: 201-405-0900Tel: (USA only) 800-631-0176Fax: 201-405-0090E-mail: sales@mikroninfrared.com

West Coast Office:Mikron4475 Dupont Court #9Ventura, CA 93003Tel: 805-644-9544Fax: 805-644-9584E-mail: sales@e2t.com

Visit our websites:www.mikroninfrared.comwww.IRimaging.com

0603 Glass Rev. 0Printed in USA

Protective Hardware

Accessories

Air Purge Mini Assemblyfor fiber optic models M68 and M668

Air Purge Assemblyfor fiber optic models M68 and M668

Air Purge with mounting bracket andceramic/ inconel sight tube for MI-S50-LO-GL and MI-S5-LO-GL

Air Purge for MI-300/5Air Purge & Water Cooling Jacketfor MI-300/5

Stainless Steel Protective coolingjacket with integrated air purge forMI-N5/5+ Sensors

Programming ModuleModel MI-HT6000 for setting MI-Seriessensor parameters

Scanning Mirror AssemblyMI-SCX Series

Protective Cooling Jacket with air purge and aiming flange assemblyfor models M67S and M770S Series

Air Purge & Water Cooling Jacketfor MI-200 or MI-N200/5 Sensors

Mikron infrared sensors are inherently rugged and reliable, but for long term accuracy and reliability, the optics must remain clean and the electronics must not be subjected to conditions exceeding ambient temper-ature specification limits. Mikron'sextensive range of protection and mounting accessories makeinstallation simple, keep mainte-nance to a minimum and ensureoptimum performance in the harshprocess environment of glass manufacturing.

M300For calibration of all infrared glassindustry sensors ranging from 200º C to 1150ºC.

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