ILX Lightwave LDT-5900 Series User Manual page 139

5
6
01_10
C A L I B R A T I O N A N D T R O U B L E S H O O T I N G
SENSOR OUTPUT CURRENT CALIBRATION
5a Select Sensor Mode and connect 100 k resistor across sensor loads.
5b Connect DMM across 100 k resistor (R
polarity.
5c Select 10 µA thermistor current from Sensor Parameter Menu.
5d Record voltage (V
sens1
5e Replace 100 k resistor with 10 k resistor (R
5f Select 100 µA thermistor current from Sensor Parameter Menu.
5g Record voltage (V
sens2
5h Replace 10 k resistor with 1 k
5i Select 1 mA thermistor current from Sensor Parameter Menu.
5j Record voltage (V
sens3
5k Calculate scale factor for each current setting from the following:
for i = 1 - 3
scalefacto
Note: Pay attention to units; scalefactor
5l Enable Cal Mode by entering the remote command MODE CAL.
5m Enter the new 10 µA scale factor via the command CAL:SOURCE:SENsor:10UA
scalefactor .
1
5n Enter the new 100 µA scale factor via the command CAL:SOURCE:SENsor:100UA
scalefactor .
2
5o Enter the new 1 mA scale factor via the command CAL:SOURCE:SENsor:1MA
scalefactor .
3
5p Save the new values to flash memory by using the CAL:SAVE command.
5q Return to Sensor Mode by using the MODE SENSOR command.
5r Enter the commands CAL:SOURCE:SENsor:10UA?,
CAL:SOURCE:SENsor:100UA?, and CAL:SOURCE:SENsor:1MA? to verify that
the factors were stored correctly.
SENSOR VOLTAGE MEASUREMENT CALIBRATION
6a NOTE: The sensor voltage measurement must be calibrated for each thermistor
current setting.
6b Select 10 µA thermistor current from Sensor Parameter Menu. Connect the 1 k
resistor (R ) to the sensor leads. Connect the DMM across the resistor as well to
sens1a
measure voltage.
6c Record voltage (V
sens1a
) to measure voltage. Pay attention to
sens1
) across 100 k resistor .
sens2
) across 10 k resistor.
resistor (R
sens3
) across 1 k resistor.
10 A
R
sens
i
r 100 A
i
V
sens
1 mA
i
is dimensionless.
i
) across R as measured by DMM.
sens1a
Ca libra t ion Procedure
).
).
LDT-5980/ 5948
5
C H A P T E R
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