THORLABS TED200C, Руководство по эксплуатации

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TED200C
3.1.4 Connecting a temperature sensor
The TED200C is compatible with a number of temperature sensor types:
· NTC (standard thermistor)
· AD590/AD592
· LM135/LM335
The temperature sensor is selected at the front ( key SENSOR - F25 ). The LED F19 to F21
indicate the selected sensor.
Temperature Ranges
·
NTC (thermistor): 2 measurement ranges - 0 to 20k
W
and 0 to 200k
W
·
AD590/AD592/LM135/LM335): the measurement range -45°C to +145°C.
·
The actual temperature control range depends on the sensor ratings and the individual
thermal setup.
If no temperature sensor is connected or if the temperature sensor does not correspond to the
selected sensor type, the LED “OPEN” (F6) lights up and the display (F1) indicates overflow
when "T
ACT
" measurement value is selected.
The temperature sensor is connected to the 15-pin D-SUB jack "TE OUTPUT" (R5) at the rear
of the TED200C depending on the used sensor type.
Note
If LM135/LM335 is used as temperature sensor, select "AD590" (key F25). The LED
"AD590" (F19) lights up.
Thermistor
A thermistor is a resistor with a N egative T emperature C haracteristic, that's why it is also known
as NTC. It's resistance decreases exponentially with the temperature.
A thermistor must be connected between pin 3 and pin 4 of the 15-pin D-SUB
jack (R5) . The polarity is not relevant, so far the thermistor is floating. If one
pin of the thermistor is grounded (for example in a laser module), this pin has to
be connected to pin3.
If the TED200C is operated with a thermistor temperature sensor, the "T
SET
"
and "T
ACT
" temperature is displayed as resistance in k
W
.
The NTC measurement current is 100µA in 20k
W
range and 10µA in 200k
W
range.
To describe the dependency of resistance vs. temperature, several algorithms
are known. A simplified method, giving good results within a range relatively close to the
reference temperature, is the exponential formula:
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