ILX Lightwave LDT-5900 Series User Manual page 142

5
C H A P T E R
7
126
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
6af Calculate the 1 mA Sensor Voltage Measurement slope and offset using the
equations below:
m
vsens
b
vsens
6ag Enable Cal Mode by entering the remote command MODE CAL.
6ah Enter the new calibration values by using the command
CAL:SENsor:VOLTage:1MA m
6ai Save the new values to flash memory by using the CAL:SAVE command.
6aj Return to Sensor Mode by using the MODE SENSOR command.
6ak Verify the correct storage of the calibration values by entering
CAL:SENsor:VOLTage:100UA?
RAC Calibration
7a NOTE: R mode and the subsequent recalibration thereof is only possible with
AC
firmware version 01.03.09 and above.
7b Select R mode and connect TE output across TE Cal resistor R
AC
highest possible accuracy, ensure TE voltage sense lines are connected to the same
points on the TE Cal resistor as the TE output.
7c Enable R measurement by sending the remote command OUTput ON
AC
7d Record the first measurement for R
MEASure:RAC?
7e Re-enable R measurement with another OUTput ON command followed by a
AC
MEASure:RAC? query and record this second R
7f Repeat this process several additional times to generate a well-defined mean value
for R .
AC1
7g Replace R with R
TE
7h Take several measurements of R
generate a well-defined mean value for R
7i Calculate the R Slope and Offset values using the following formulae:
AC
m
b
RAC
V V
sens 3 b sens 3 a
3
V V
3 b 3 a
V m V
3 sens 3 b vsens 3 3 b
, b
vsens3 vsens3
by querying the instrument with
AC1
Cal resistor R .
AC RAC
using OUTput ON and MEASure:RAC? to
RAC
.
AC2
R R
RAC TE
RAC
R R
AC 2 AC 1
R m R
RAC RAC AC 2
.
. To ensure
TE
measurement.
AC1