Extech Instruments 7470 Operation Manual page 77

ACW Voltage, 10KV
T E S T
e
Connect an AC standard voltage meter for 7470 and 7473 or a DC standard voltage
meter for 7472 and 7474 which can measure up to 10KV to the output connectors and
then press the TEST button, the program will automatically generate an output of about
10KV and the display will show:
HI-Voltage =
Enter Standard V-out
Use the Numeric keys to enter the standard value of voltage, unit V, and then press the
ENTER key to store the standard value of AC or DC hipot voltage for calibration and
display will show:
ACW Voltage, 10KV
T E S T
e
11.3.2. Calibration of 7470 AC Hipot Current
AC Hipot, 20mA current range
Press the  key, the program will advance to the AC 20.00mA range calibration of the
hipot test. The display will show:
AC 20.00mA, 100K
T E S T
e
Connect a resistor about 100K/40W in series with a AC standard Ammeter which can
measure up to 20.00mA to the output leads. The Ammeter should be connected to
the return lead, then press the TEST button, the program will automatically generate an
output of about 2000V/20mA and the display will show:
Current =
Enter Standard I-out
Use the Numeric keys to enter the standard value of current, unit mA, and then press
the ENTER key to store the standard value of AC 20.00mA range for calibration and the
display will show:
AC 20mA, 100K
T E S T
e
t o C a l i b r a t
V
OK
t o C a l i b r a t
t o C a l i b r a t
mA
OK
t o C a l i b r a t
or DCW Voltage, 10KV
T E S T
e
or DCW Voltage, 10KV
OK
T E S T
e
t o C a l i b r a t
t o C a l i b r a t
73