HP 3457A Service Manual page 126

Calibration 3457A
3. Access the Calibration Command. (Press the Blue SHIFT key, then the OFFSET COMP /C
configuration key). The display will show CAL.
4, Enter the value of the input resistance (in ohms). (NOTE: If the security feature has not been disabled
(set to 0), it will be necessary to enter the input value, the delimiter ( , ) and the security code). 5. Press the ENT
key. The display will show CALIBRATING while the calibration routine is running.
d. Repeat steps "cl" through "c5" for each of the remaining ranges.
e, Disconnect the resistance standard from the 3457A input terminals.
5-31, Four-Wire Ohms Offset Calibration - Front Terminals
§-32. Equipment Required. A low thermal short (copper wire) is required for this procedure. (Refer to
Figure 5-1).
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Figure 5-1. Input Connections for Four-Wire Ohms Offset Calibration
a, Select the 4-Wire Ohms Function. (Press the Blue SHIFT key, then the OHM / OH MF key),
b, Connect the short across the Front Panel HI and LO Input Terminals and the Q Sense HI and LO
terminals as shown in Figure 5-1.
c. Use the following procedure to calibrate the front terminal offset on the 30 Mohm, 3 Mohm,
300 Kohm, 30 Kohm, 3 Kohm, 300 Ohm and 30 Ohm ranges beginning with the 30 Mohm range.
1. Set the 3457A to the appropriate resistance range. (Use the t or 1 scroll keys to select the proper
range).
2. Access the Calibration Command. (Press the Blue SHIFT key, then the OFFSET COMP / C configura-
tion key). The display will show CAL.
3, Enter the value of the input - in this case 0. (NOTE: If the security feature has not been disabled (set to
0), it will be necessary to enter the input value, the delimiter (,) and the security code).
4. Press the ENT key. The display will show CALIBRATING while the calibration routine is
running.