Newport LDC-3706 Series, Руководство пользователя

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December 2019 34 LDC-3706 Series Laser Controller
RTD SENSORS – When an RTD sensor is selected, the LDC-3706 measures temperature
based on the resistance of the sensor. An example of an RTD sensor is the Xian Diamond USA
T2001SDL. This device has a positive slope and a nominal resistance at 0°C of 100 ohms. Two
wire RTDs should be connected across the and Sensor- pins (pins 7 and 8).
The resistance versus temperature function for typical platinum RTDs is accurately modeled by
the Callendar-Van Dusen equation, as shown below.
1 100 − For T ≤ 0
°
C
1 For T > 0
°
C
where:
Ω 0
Ω °
°
The IEC 60751 Callendar-Van Dusen constants are listed below and are used as default values
in the LDC-3706 Laser Diode Controller.
3.908 ∗ 10
− 5.775 ∗ 10
− 4.183 ∗ 10
For optimal accuracy and stability, the 1 mA current source should be selected for RTD sensors
with resistance of 200
Ω to 1500 Ω and the 2.5 mA range should be used with resistance of 1 Ω
to 200 Ω . In general, the change in resistance per change in temperature is much lower for a
typical 100 Ω RTD than that of a typical 10 k Ω thermistor. The proportional and integral terms
for the PID loop must be increased appropriately when using an RTD sensor for optimal setting
time and stability.