HP 3457A Service Manual page 85

Operational Verification Tests
4-Wire Ohms Operational Verification Tests Cont'd
3457A
1 n p u t
S h o r t
S h o r t
S h o r t
3457A
Range
3 Kohm
30 Kohm
300
Kohm
3457A
S e t Up
O H M F
O H M F
OHMF
Table 4-27. 4-Wire Ohms Offset Test Limits
90 d a y L i m i t s
0.000007
Kohm
00.00007
Kohm
000.0008
Kohm
(
I a K a
STAT
1 y e a r l i m i t s
0.000007
Kohm
00.00007 Kohm
000.0008
Kohm
I
Figure 4-1 8. 4-Wire Ohms Operational Verification Test Connections
4-86. 4-Wire Ohms Function
-
Gain Test
4-87. Equipment Required.
Resistance Standards of 3 Kohnx
( 2
.0010/(~), 30 Kohrns
(1
.001%) and
300 Kohms
(+
.001%) are reyuired for this procedure.
1. Set the HP 3457A to the 4-Wire ohms function (OHMF) and the n ~ ~ n i b e r of digits displayed (DIGITS
DISP) to six.
2. Connect the appropriate Resistance Standard to the H P 3457A front panel input terminals as shown
in Figure 4-18.
3.
Use the Test Record to record the resistance readings for the 3 Kohm,
30
Kohm and
300
Kohm
ranges.
4. If any of the readings are beyond the limits specified in Table 4-28 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.