HP 3457A Service Manual page 82

3457A
Operational Verification Tests
AC Current Operational Verification Tests
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Figure 4-15. ACI Operational Verification Test Connections
4-78. AC Current Function - Gain Test
4-79, Equipment Required, An AC Current Source capable of providing a current of 300 mA (+ .1%) at a
frequency of | KHz is required for the following test.
1, Set the AC Current source for an output of 0 mA and connect it to the HP 3457A front panel I
and LO input terminals.
2. Set the HP 3457A to the 300 mA range and the number of digits displayed (DIGITS DISP) to six.
Set the AC Current Source for an output of 300 mA at a frequency of 1 KHz.
3. Use the Test Record to record the 300 mA full-scale reading.
4, If the full-scale reading is beyond the limits specified on the Test Record (301.0300 mA - 298.9700
mA), the instrument should be calibrated or repaired. Refer to Section V for calibration procedures.
5. Reduce the output of the AC Current Source to 0 and disconnect it from the HP 3457A input
terminals.
2-Wire Ohms Operational Verification Tests
4-80. 2-Wire Ohms Function - Offset Test
4-81. Equipment Required. A low thermal short (copper wire) is required for this procedure.
1, Connect a low thermal short across the HP 3457A front panel HI and LO input terminals.
2. Set the HP 3457A to the 2-Wire Ohms Function, 3 Kohm range and the number of digits displayed
(DIGITS DISP) to six.
3. Use the Test Record to record the offset readings for the 3 Kohm, 30 Kohm and 300 Kohm ranges.
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