Fluke 8508A User Manual page 167

For the 2 G range use the 1 G standard resistor in place of the calibrator. To avoid the
requirement for a 10 G standard, the 20 G range is automatically calibrated when the
2 G range gain calibration is triggered. It is also necessary for the 100 M and 1 G
Normal ranges to be calibrated prior to the 2 G HiV range for the result to be valid.
A 10 G standard resistor may be used for calibrating the 20 G range if available, but
if performed, this operation must take place after the 2 G range gain point calibration to
avoid the automatic process overwriting the result.
Voltages of approximately 200 V will be developed across the resistance standard at full
scale, ensure the resistance standards used are suitable for operation at these voltages.
Note that EX SNS (4-wire) is not available on the 5720A 100 M range, and the 8508-
7000K 1 G standard resistor is used as a 2-wire device with the calibrator 2-wire
resistance zero used for the corresponding zero points.
when calibrating the 200 M and 2 G range, range zero, and range gain points.
On each range, the 8508A automatically recognizes the appropriate value as range zero or
range gain from the applied resistance value.
It is unlikely that the resistance standard will be at exactly the nominal value
required. The Set feature allows a user to enter the true output value of the
calibration standard where it differs from nominal range gain point. If the
resistance value is exactly the nominal value required, omit steps 2-4 for the
Range Gain Point .
Zero Point
1. On the 8508A, select the required range.
2. On the Calibrator, select zero
select Ex SNS on the calibrator and de-select
using a standard resistor connect the standard resistor for a 4-wire resistance zero.
3. On the 8508A, press
4. Press
SAMPLE
Calibration is complete when the Busy legend goes out and the calibrated
measurement is displayed.
Range Gain Point
1. On the Calibrator, select Range Gain point Output value. Alternatively if using a
standard resistor re-connect the standard resistor to measure its resistance. (For the
2 G range the 8508-7000K 1 G standard resistor is used in place of the calibrator.
For the 200 M range and above, de-select Ex SNS on the calibrator and de-select
n the 8508A. Calibration of the 20 G range gain point takes place
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automatically when calibrating 2 G range, and calibration against an external
standard is optional if a suitable standard is available).
2. On the 8508A, Press
3. Select on the
Set
4. Use the numeric keys with the
the calibrator (or the value of the resistance standard) at the range gain value, then
press Enter.
Note
and Operate. (For the 200 M range and above, de-
to enter the
CAL CALIBRATION
to initiate the calibration operation.
to revert to
CAL CALIBRATION
.
CALIBRATION menu
SET VALUE
Calibration and Verification
is deselected on the 8508A
4W
n the 8508A.) Alternatively if
4W
menu.
menu.
menu to key in the true output value of
6
Routine Calibration
6-23