Keithley 2790, User Manual, Page: 20 / 130

Model 2790 SourceMeter
®
Switch System User’s Manual 1-9
Insulation resistance (HIPOT) test (7751 and 7753 only)
WARNING The Models 7751 and 7753 are provided with outputs that are poten-
tially hazardous if not connected properly. It is the responsibility of the
customer to operate instruments in a safe manner. Be sure to read and
follow all installation and operating instructions before attempting to
use the 7751/7753 HIPOT function.
The leakage resistance (R
HIPOT
) between each of the initiators and the housing must be
verified. As shown in Figure 1-4 , this is performed by applying a voltage, typically 500V,
between the bridgewire and the housing. The resultant test circuit current is applied to an
I/V amplifier, where it is converted to a voltage. This voltage is then measured by the
DMM of the Model 2790.
NOTE If not using a 7751/7753 module in your test system, resistance up to 120M Ω
can be measured using the Ω 2 function of the Model 2790.
Figure 1-4
HIPOT testing (7751/7753)
V
SOURCE
(500V)
R
HIPOT
+
R
F
I/V Amplifier
(7751/7753)
+
–
2790
DMM
v
R
HIPOT
= –
V
SOUR
V
MEAS
x R
F
= –
500V
V
MEAS
Keithley 2790 SourceMeter Switch System
Keithley 7751/7753 Module
x R
F
R
F
= 200k
Ω
(7751)
R
F
= 20k
Ω
(7753)