Rtd Sensor Calibration - Newport LDC-3706 Series User Manual

RTD Sensor Calibration

The following procedure calibrates the 1 mA and 2.5 mA RTD temperature sensors so that the
resistance measurements will be accurate. This procedure does not calculate R
For information on calibrating the RTD sensor itself, see Application Note #4 Thermistor
Calibration and the Steinhart-Hart Equation.
1 mA RTD
1. Measure and record the exact resistance of a 300Ω and 1200Ω metal film resistor.
A 4-point probe resistance measurement is recommended.
2. Connect the 300Ω resistor to the sensor pins of the 15-pin output connector of the LDC-
3726 (pins 7 and 8) or the 25-pin output connector of the LDC-3736/LDC-37620 (pins 14
and 15).
3. Enter the sensor calibration mode by navigating to the "RTD1mACal" selection in the
Sensor Cal area of the Calibration submenu of TEC parameter menu tree.
4. Select the appropriate RTD calibration selection by pressing the SET button when the
title for that calibration procedure is shown on the display, then press the TEC button in
order to enable the sensor current.
5. Turn the ADJUST knob until the display indicates the same resistance recorded for the
300 Ω resistor. Press the TEC button.
6. Connect the 1200Ω resistor to the sensor pins.
7. Turn the ADJUST knob until the display indicates the same resistance recorded for the
1200 Ω resistor. Press the TEC button.
Wait for the 7-segment display to exit the calibration mode and reflect the entered
8.
sensor resistance setpoint. Once the calibration is completed, the calibration constants
will be stored to the non-volatile memory and the display will return to its previous state.
2.5 mA RTD
1. Measure and record the exact resistance of a 60Ω and 240Ω metal film resistor. A 4-
point probe resistance measurement is recommended.
2. Connect the 60Ω resistor to the sensor pins of the 15-pin output connector of the LDC-
3726 (pins 7 and 8) or the 25-pin output connector of the LDC-3736/LDC-37620(pins 14
and 15).
3. Enter the sensor calibration mode by navigating to the "RTD2mACal" selection in the
Sensor Cal area of the Calibration submenu of TEC parameter menu tree.
4. Select the appropriate RTD calibration selection by pressing the SET button when the
title for that calibration procedure is shown on the display, then press the TEC button in
order to enable the sensor current.
5. Turn the ADJUST knob until the display indicates the same resistance recorded for the
60Ω resistor. Press the TEC button.
6. Connect the 1200Ω resistor to the sensor pins.
7. Turn the ADJUST knob until the display indicates the same resistance recorded for the
240Ω resistor. Press the TEC button.
8. Wait for the 7-segment display to exit the calibration mode and reflect the entered
sensor resistance setpoint. Once the calibration is completed, the calibration constants
will be stored to the non-volatile memory and the display will return to its previous state.
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LDC-3706 Series Laser Controller