HP 3457A Service Manual page 81

Operational Verification Tests 3457A
DC Current Operational Verification Tests Cont'd
3457A |3457A | 34570 90 day limits 1 year limits
Input | Range | Set Up High Low High Low
Open 3 ma| oct +0.000104 ma 0.000104 mA +0.000104 ma 0.000104 ma
Open 1A | vcr +00.00604 ma -00.00604 mA +00.00604 mA -00.00604 ma
3 ma| 3 mal oct 3.000704 ma 2.999296 mA 3.001304 mA 2.998696 mA
300 ma] 1A | ocr 0.300814 A 0.299186 A 0.300844 A 0.299156 A
Table 4-24. DC Current Test Limits
4-74, DC Current Function - Offset Test
4-75.
4-76.
4-77.
Equipment Required. This procedure does not require any test equipment.
1, Set the HP 3457A to the DC Current function (DCI), 3 mA range, and the number of digits dis-
played (DIGITS DISP) to six.
2. Use the Test Record to record the current offset readings on the 3 mA and I A ranges.
3. If either of the offset readings are beyond the limits specified in Table 4-24 and on the Test
Record, the instrument should be calibrated or repaired. Refer to Section V for calibration
procedures. e
DC Current Function - Gain Test
Equipment Required. A DC Current Source capable of providing currents of 3 mA and 300 mA
(+ 007%) is required for the following procedure.
I. Set the DC 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 3 mA range and the number of digits displayed (DIGITS DISP) to six. Set
the DC Current Source to 3 mA.
3. Use the Test Record to record the 3 mA full-scale current reading,
4, Set the HP 3457A to the | A range and set the DC Current Source for an output of 300 mA.
5. Use the Test Record to record the 300 mA reading.
6. If either of the readings are beyond the limits specified in Table 4-24 and on the Test Record, the
instrument should be calibrated or repaired. Refer to Section V for calibration procedures.
7. Set the output of the DC Current Source to 0 and disconnect it from the HP 3457A input
terminals.
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