2-Wire Ohms F ~ ~ N C T I O N Offset Test; 2-Wire Ohms Function . Gain Test; Verification Tests - HP 3457A Service Manual

Operational Verification Tests
AC Current Operational Verification Tests
A
C
CURRENT
\
I
SOURCE
Figure 4-1 5. 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
(+
.I%) at a
frequency of 1 KHz is required for the followiilg test.
I.
Set the AC Current source f o r an output of 0 mA and connect it t o the HP 3457A front panel
1
and
LO
input terminals.
2. Set the HP 3457A to the 300 mA range and the number of digits displayed (DIGITS DISP) t o six.
Set the AC Current Source for an output of 300 niA at a frequency of 1 KHz.
3. Use the Test Record t o 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 H P 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 f o r this procedure.
1. Connect a low thermal short across the HP 3457A front panel HI and LO input terminals.
2. Set the HP 3457A t o 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 f o r the 3 Kohm, 30 Kohm and 300 Kohm ranges.