ILX Lightwave LDT-5900 Series User Manual page 138

5
C H A P T E R
4
122
LDT-5980/ 5948
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
Ca libra t ion Procedure
3l Save the new values to flash memory by using the CAL:SAVE command.
3m Return to ITE Mode by the MODE ITE command.
3n To verify that the calibration values were correctly saved, query the instrument with
the CAL:ITE? command.
ITE OUTPUT CALIBRATION
4a Set output to -5.000 A (-4.500 A if 5948 to prevent current limit from enabling) and
connect the DMM (Digital MultiMeter) across the TE Cal resistor to measure voltage.
Pay attention to polarity.
4b Allow one minute for current to stabilize if output has just been enabled.
4c Record the TE voltage (VTE
4d Set output to +5.000 A (+4.500 A if 5948).
4e Record VTE .
DMM2
4f Disable output.
4g Calculate the ITE Output Slope and Offset using the following formulae:
For Model 5948
m
ITE
For Model 5980
m
ITE
For Model 5948
b
ITE
For Model 5980
b
ITE
4h Enable Cal Mode by entering the remote command MODE CAL.
4i Enter the new calibration values using the command: CAL:COARSEDAC m
4j Save the new values to flash memory by using the CAL:SAVE command.
4k Return to ITE Mode by the MODE ITE command.
4l Verify the calibration values are correct by using the query CAL:COARSEDAC? to
check them.
) as measured by the DMM.
DMM1
9 0 . R
TE
VTE VTE
DMM 2 DMM 1
10 0 . R
TE
VTE VTE
DMM 2 DMM 1
VTE
DMM 2
4 5 . m
ITE
R
TE
VTE
DMM 2
5 0 . m
ITE
R
TE
, b
ITE ITE