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Page 64 of 102
923 milliK manual - issue: 1.10
Press the
Numeric
(F1) key, select channel 3, clear the statistics and wait for 100
measurements to be made (when the display shows “Mean of 100”). The mean value
indicated by the milliK is the zero reading for current measurements.
Connect a calibrated (nominally) 10mA current source to channel 3 (rear panel):
10mA
Calibrated Current Source
Clear the statistics and wait for 100 measurements to be made. The measurement system is
very low noise so it is likely that you will see the readings dithering between 2 values
separated by the milliK’s current resolution (<0.001mA). The mean value indicated by the
milliK should be compared with the current source’s calibrated value.
5.2.6 Reference Junction Compensation Accuracy
Check the accuracy of the internal reference junction compensation (RJC) system by
connecting a thermocouple to the milliK and measuring a know temperature using internal
RJC mode. Any discrepancy between the measured and known temperature indicates an error
in the RJC system (or the thermocouple used). You can use any thermocouple type for the
measurement, but we recommend type J thermocouples as these have high sensitivity near