HP 3457A Service Manual page 132

Calibration
5-51. Four-Wire Ohms Offset Calibration
-
Rear Terminals (Standard Instrument)
5-52. Equipment Required. A low thermal short (copper wire) is required for this procedure.
a. Short the
+
SENSE HI and LO and INPUT HI and LO rear input terminals together.
b. Select the rear input terminals.
(Press the T E R M configuration key, eater the number 2 and press the E N T
key
1.
c. Select the 4-Wire Ohms function.
(Press the Blue S H I F T key, then the O H M
/
O H M F function key).
d. Use the following procedure t o calibrate the rear terminal offset on the 30 Mohm, 3 Mohm,
300 Kohm, 30 Kohm, 3 Kohm, 300 Ohm and 30 Ohm ranges beginning with the 30 Mohm range.
I. Set the 345714 t o the appropriate resistance range.
( u s e the
f
or
, / ,
scroll keg t o select the proper
range).
2. Access the Calibration command.
(Press the Blue S H I F T key, then the OFFSET C O M P
/
C configura-
tion key).
The display will show CAL.
3. Enter the value of the input
-
in this case 0.
( N O T E : I f the security feature has not been disabled (set t o
O), it will be necessary t o enter the input value, the delimiter
(
,
)
and the security code).
4. Press the ENT key. The display will show CALIBRATINa while the calibration routine is
running.
e. Repeat steps
"
d l
"
through
"
d4
"
for each of the remaining ranges.
5-53. DC Current Offset Calibration
-
Rear Terminals (Standard Instrument)
5-54. Equipment Required.
No
equipment is needed for this procedure.
a. Select the rear input terminals.
(Press the T E R M configuration key, enter the number 2 and press the E N T
key
).
b. Select the DC Current function.
(Press the DCI function key).
c. Use the following procedure t o calibrate the rear terminal offset on the
300 uA, 3 mA, 30 mA,
300 mA, and 3 A ranges beginning with the 3 A range.
I. Set the 3457A t o the appropriate current range.
(Use the
or
5.
scroll key t o select the proper range).
2.
Access the Calibration command.
(Press the Blue S H I F T key, then the OFFSET C O M P
/
C configura-
tion key).
The display will show CAL.
3.
Enter the value
of the
input
-
in this case
0.
(NOTE:
I f
tho
security feature has not been disabled (set t o
0), it
will be necessary t o enter the input value, the delimiter (
,
) and the security code).
4. Press the ENT key. The display will show CALIBRATINQ while the calibration routine is
running.
d. Repeat steps
"
c l
"
through
"
c4
"
for each of the remaining ranges.