HP 3457A Service Manual page 129

3457A Calibration
5-39. AC Volts Offset 81 Gain Calibration
-
Front Terminals
5-40. Equipment Required. An AC Voltage Source capable of providing 30 mVrms, 300 mVrms, 1 Vrms,
2 Vrms, 3 Vrms, 30 Vrms and 300 Vrms (fO.lO/o) at a frequency of 1 KHz is required t o calibrate the AC
Voltage Function.
a. Select the AC Voltage function.
(Press the ACY function key).
b. Run the AC Auto-Calibration routine.
(Press the AUTO CAL configuration key, enter the number 2 and press
the ENT key).
c. Set the AC Voltage Source t o provide a 3 volt, 1
kHz
signal and connect it t o the front panel
HI
and LO input terminals.
The 34574 must be calibraled on lhe 3 volt range before calibrufing the ofhcr
ranges. This is became the offset constant for all ac voltage and ac cwrent ranges
is comprrfcd whilc calibrating the 3 Vuc rangc.
d. Set the 3457A to the 3 volt range.
(Use the or
scroll keys t o select the proper range).
e. Use the following procedure to calibrate the Gain on the 30 mV, 300 mV, 3 V, 30 V and 300 V AC
ranges beginning with the 3 V range.
1. Set the 3457A t o the appropriate voltage range.
(Use the
1
or
5.
scroll key t o select the proper range).
2. Set the output of the AC voltage source to provide a full-scale reading on the HP 3457A.
3. Access the Calibration Command.
(Press the Blue SHIFT key, then the OFFSET C O M P
/
C configurn-
tion key).
The display will show CAL.
4. Enter the value of the input voltage (in volts).
(NOTE: If the security feature has not been disabled (set
t o 0), it will be necessary t o enter the input value, the deliniiter
(
,
)
and the security code).
5. Press the
ENT
key. The display will show CALIBRATING while the calibration routine is
running.
f. Repeat steps
"
e l
"
through " e4
"
for each of the remaining ranges.
g. Set the output of the AC Voltage Source to 0 and disconnect it from HP the 3457A.
5-41. AC Current Calibration
-
Front Terminals
5-42. Equipment Required. An AC Current Source capable of providing 30 mA (+.14%), 300 mA
(f
.l4%)
and 1 A
(f
A % ) at a frequency of 1 KHz is required to calibrate the AC Current Function.
a. Select the AC Current function.
(Press the ACI function key).
b. Set the AC Current Source to provide an output of 30 mA and connect it t o the HP 3457A front
panel
I
and
LO
input terminals.