Keithley 7037, Instruction Manual

Page: 43 / 72

Operation
5-10
Ground loops are not normally a problem with instruments
having isolated LO terminals. However, all instruments in
the test setup may not be designed in this manner. When in
doubt, consult the manual for all instrumentation in the test
setup.
Keeping connectors clean
As is the case with any high-resistance device, the integrity
of connectors can be damaged if they are not handled prop-
erly. If connector insulation becomes contaminated, the insu-
lation resistance will be substantially reduced, affecting
high-impedance measurement paths.
Oils and salts from the skin can contaminate connector insu-
lators, reducing their resistance. Also, contaminants present
in the air can be deposited on the insulator surface. To avoid
these problems, never touch the connector insulating mate-
rial. In addition, the Model 7037 card should be used only in
clean, dry environments to avoid contamination.
If the connector insulators should become contaminated,
either by inadvertent touching or from airborne deposits,
they can be cleaned with a cotton swab dipped in clean meth-
anol. After thorough cleaning, they should be allowed to dry
for several hours in a low-humidity environment before use,
or they can be dried more quickly using dry nitrogen.
AC frequency response
The AC frequency response of the Model 7037 is important
in test systems that switch AC signals. Refer to the specifica
tions at the front of this manual.