Dc Voltage Function - HP 3457A Service Manual

Performance Tests
Rear Input Performance Tests (44492A 10 Channel Multiplex Assy)
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I 1
4 4 4 9 2 A R E L A Y
I
SHORTING WIRES
Figure 4-1 1. HP 44492A Terminal Block Assembly Connections
4-58. Preliminary Steps
I.
Connect shorting wires t o the inputs of the Terminal Block assembly as shown in Figure 4-1 1.
2. Select the Scanner Input. (Press the
TERM
configuration key, enter the number
2
and press the
ENT
key).
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4-59. DC Voltage Function
-
44492A Offset Test
4-60. Equipment Required.
A
low thermal (copper) shorting wire is required f o r this procedure.
1. Set the H P 3457A t o the DC Voltage function (DCV) and the number of digits displayed (DIGITS
DISP) t o six.
2. Close channel 0. (Press the
CHAN
c o n f i g ~ ~ r a t i o n key, enter the number 0 and press the
ENT
key).
3. Test the HP 3457A input offset o n the 300 V, 30 V, 3 V, and 300 rnV ranges and record t h e reading
of each range o n the Test Record provided a t the end of this section. Begin with the
300 V range t o
allow any thermal voltages which might affect the readings o n the lower ranges t o dissipate.
4. Test the H P 3457A input offset o n channels 0 through 9 with the instrument set t o t h e 30 m V
range. Record the reading of each channel o n the Test Record provided a t the end o f this section.
5.
If any of the offset readings are beyond the limits specified in Table
4-19 and o n the Test Record,
the instrument should be calibrated o r repaired. Refer t o Section V of this manual f o r calibration
procedures.