HP 3457A Service Manual page 83

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Operational Verification Tests 3457A
2-Wire Ohms Operational Verification Tests Cont'd
SENSE INPUT
TAST a
im fri FILTER
CIC
Figure 4-16. 2-Wire Ohms Operational Verification Test Connections
4. If any of the offset readings are beyond the limits specified in Table 4-25 and on the Test Record,
the instrument should be calibrated. Refer to Section V of this manual for calibration procedures.
5. Remove the short from the front panel input terminals.
34570 34570 34578 90 day limits 1 year limits
Input Range | Set Up
Short 3 Kohm | OHM 0.000207 Kohm | 0.000207 kohm
Short 30 Kohm | OHM 00.00027 Kohm | 00.00027 Kohm
Short |300 Kohm | OHM 000.0010 Kohm | 000.0010 Kohm
Table 4-25. 2-Wire Ohms Offset Test Limits
4-82. 2-Wire Ohms Function - Gain Test
4-83. Equipment Required. Resistance Standards of 3 Kohms (+ .001%),
300 Kohms (+ 001%) are required for this procedure.
30 Kohms (+ 001%), and
LSet the HP 3457A to the 2-wire ohms function (OHM) and the number of digits displayed (DIGITS
DISP) to six.
2. Connect the Resistance Standard to the HP 3457A front panel HI and LO input terminals. (The
connecting wires should be as short as possible to reduce lead resistance).
3. Use the Test Record to record the 3 Kohm, 30 Kohm and 300 Kohm full-scale readings.
4. If any of the readings are beyond the limits specified in Table 4-26 and on the Test Record, the in-
strument should be calibrated. Refer to Section V of this manual for calibration procedures.
5. Remove the Resistance standard from the HP 3457A front panel input terminals.