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DRAWING TOWER THERMOMETER - DTT
Drawing Tower Thermometer - DDT  
In order to draw high quality low loss optical fibre with the required strength and attenuation the temperature of the drawing tower furnace must be stable and precisely controlled.
The furnace lining can get close to melting point so its temperature is monitored and used as the heating control parameter.

 
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Measurement Problems
Graphite resistance and Induction-heated zirconia furnaces operating at high temperatures, typically 2200C/4000F, make contact methods of temperature measurement impractical.
The thermometer requires a small target size to view between the coils in an induction heated furnace, or sight down a narrow tube on to the zirconia susceptor.
In the case of a graphite resistance type furnace the thermometer has to sight through a quartz window, down through a narrow tube onto the heating element.
Experience has shown outstanding benefits by using short wavelength thermometers, for this application in order to achieve maximum accuracy.
A silicon cell detector gives high stability, rapid response and high rate of change of output with temperature.
A small target size is offered, with a measurement spot size of 4mm/0.15in diameter at the focus distance of 450mm/17.7in.
The thermometer provides high level signal to noise output for retransmission to a readout or control system Individually calibrated thermometers are available with traceability to National Standards. UKAS or NIST Calibration certificates are available.

Features
2m/6.5ft light guide length
Small target capability
Rugged, flexible, modular design
Accurate, reliable, drift-free measurement
Standard industry mounting
Industry standard outputs to suit any process monitoring, recording or control system

  Specifications      
  Model:
DTT 800/2600C
DTT 1500/4700F
 
  Temperature range
   Operating:

800 to 2600C

1500 to 4700F
 
     Specified:
1000 to 2600C
1830 to 4700F
 
  Wavelength:
1m
 
  Response time:
Adjustable 5ms to 5s (0 to 95%)
 
  Emissivity:
Emissivity adjustable 0.10 to 1.00
 
  Output:
4 to 20mA
 
  Field of view (Nominal):
112:1
 
  Target dia: DT1 optic head:
4mm at 450mm/0.15in at 17.7in
 
  Accuracy
   Repeatability:
   Absolute:

<2C/4F
<0.75%K
 
  Stability
   Temperature:

0.3/amb
 
   Time:
2C/4F/year
 
  Vibration:
3g any axis, 10 to 300Hz
 
  Humidity:
0 to 99% non condensing
 
  Sealing:
To IP65 requirements
To NEMA 4X requirements
 
  Ambient temperature      
     Optic head:
200C/392F
 
     Light guide:
200C/392F
 
     Detector      
        Specified:
0 to 70C/32 to 158F
 
        Operating:
-10 to 80C/14 to 176F
 
  Weight:
1.7kg/3.75lb
 
  CE:
EN 50-082-2 (immunity), EN 50-081-1 (emission), IEC 1010 (safety)

 
 
Literature download on this product is available here
Last Modified (25/07/02) (59KB).
If you would like more detailed product information please use the Further Information page.

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