Fluke 9100 User Handbook Manual page 201

10.3.4.3 Determining the Output Error at the Selected Target Value
The output error of the 9100 is determined by connecting a suitable measuring instrument
to the calibrator's front-panel terminals to measure the actual analog output value, then
determining the difference between this measured value and the selected target value.
N.B.The chosen measuring instrument must have an absolute accuracy considerably
better than the accuracy specification of the 9100. (For information on suitable
measuring equipment see Appendix 10-A1 at the end of Section 10. in this handbook.)
The process of calibrating the 9100 will correct this output error. The procedure has 3
stages:
1. Set the displayed output value (output control value) to the target value by pressing
the TRANSFR (Transfer) key, then turn the calibrator output ON.
2. Increment or decrement the calibrator output using the cursor controls and/or
spinwheel until the externally measured value is equal to the target value displayed
in the lower left corner of the 9100 screen.
3. Press the CALIB (Calibrate) screen key.
The 9100 reverts to show a function screen with the displayed output value equal to the
target value, and both equal to the externally-measured output value (to within normal
measurement errors; e.g. within noise limits). The 9100 is now calibrated at that Factor's
target value, and the corresponding (digital) correction value has been stored in non-
volatile RAM.
This correction factor is derived from the amount that the output value had to be
incremented or decremented in stage (2) of the calibration process, in order to obtain an
external measurement equal to the target value (a measure of the output error before
calibration).
In order to correct the full span of values generated by the hardware configuration, the
calibration process is repeated for each of the configuration's 'Factors', and the
corresponding corrections are stored. Subsequently, when in normal operation, the 9100
applies all the stored correction factors to the output in proportions determined by an
internal algorithm; ensuring that the hardware configuration generates outputs which are
all within the accuracy specification.
After a successful calibration of the 9100 at a target calibration value, the new target value
will replace the corresponding old target value in the 'SAVED CALIBRATION FACTORS'
display. Note that on the target selection screen the target value will change only if the
new and the old target values were different.
Section 10: Calibrating the Model 9100: Standard Calibration — Basic Sequences
Final Width = 215mm
10.3-11