HP 3457A Service Manual page 130

Calibration 3457A
c. Use the following procedure to calibrate the AC Current function on the 30 mA, 300 mA and 1 A
ranges beginning with the 30 mA range.
1.
Set the 3457A to the appropriate current range. (use
the
'/'
or
4
scroll key t o select the proper range).
2. Set the current source to provide a full-scale reading on the HP 3457A range selected.
3. 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.
4. Enter the value of the input current (in amps).
(NOTE: I f the security feature has not been disabled
(set t o 0 ) , i t will be necessary t o enter the input value, the delimiter (
,
) and the security code).
5. Press the
ENT
key. The display will show CALIBRATING while the calibration routine is
running.
d. Repeat steps
I'
c l
"
through
"
c5
"
for each of the remaining ranges.
e. Set the Current Source for an output of 0 and disconnect it from the HP 3457A.
5-43. Frequency Calibration
-
Front Terminals
5-44. Equipment Required. A Frequency Generator capable of providing a single sine-wave signal between
100 Hz and 1 MHz with a frequency accuracy of
f
.OO3%) is required to calibrate the Frequency Function.
a. Set the 3457A t o the Frequency function.
(Press the FREQ function key).
b.
Set the Frequency Source to a known frequency between 100 Hz and 1 MHz and connect it t o the
HP 3457A front panel HI and LO input terminals.
c. Access the Calibration command.
(Press the Blue S H I F T key, then the OFFSET C O M P
/
C configuration
key).
The display will show
CAL.
d. Enter the value of the input frequency (in hertz).
(NOTE: If the security feature has not been disabled (set
t o 0 ) , i t will be necessary t o enter the input frequency, the delimiter
(
,
)
and the security codc).
e. Press the ENT key. The display will show CALIBRATINQ while the calibration routine is running.
f, Disconnect the Frequency Source from the HP 3457k
5-45. CALIBRATION PROCEDURES
-
REAR PANEL INPUTS
5-46. The following paragraphs describe the calibration process for the HP 3457A rear panel inputs.
Separate procedures are provided for the standard instrument (Rear Input Terminals), and instruments
equipped with optional plug-in assemblies 44491A (General Purpose Relay Assembly) and 44492A (Reed
Relay Multiplex Assembly). Select the procedure which applies t o your instrument.
5-47. DC Volts Offset Calibration
-
Rear Terminals (Standard Instrument)
5-48. Equipment Required.
A
low thermal short (copper wire) is required for this procedure.
a. Short the f 2 SENSE HI and LO and INPUT HI and LO rear input terminals together.