Keithley 7013-C, Инструкция по эксплуатации

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Operation
4-12
Instrument 1 Instrument 2 Instrument 3
Power Line Ground
Signal Leads
Ground Loop
Current
Figure 4-11
Power line ground loops
Instrument 1 Instrument 2 Instrument 3
Power Line Ground
Figure 4-12
Eliminating ground loops
4.5.5 Keeping connectors clean
As is the case with any high-resistance device, the
integrity of connectors can be damaged if they are not
handled properly. If connector insulation becomes con-
taminated, the insulation resistance will be substan-
tially reduced, affecting high-impedance measurement
paths.
Oils and salts from the skin can contaminate connector
insulators, reducing their resistance. Also, contami-
nants present in the air can be deposited on the insula-
tor surface. To avoid these problems, never touch the
connector insulating material. In addition, the 7013
card should be used only in clean, dry environments to
avoid contamination.
If the connector insulators should become contami-
nated, either by inadvertent touching, or from
air-borne deposits, they can be cleaned with a cotton
swab dipped in clean methanol. After thorough clean-
ing, 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.
4.5.6 AC frequency response
The AC frequency response of the Model 7013 is
important in test systems that switch AC signals. Refer
to the specifications at the front of this manual.