Agilent Technologies 34420A User Manual

Output Clamping
(Dry Circuit Testing)
Resistance measurements on certain types of contacts may require a
limitation on the voltage levels used to make the measurement. Both the
open circuit and the measurement voltage should be considered. The
need for voltage limitation arises from the possibility that oxidation on
the contact surfaces may increase the resistance reading. If the voltage is
too high, the oxide layer may be punctured resulting in a lower resistance
reading.
The meter provides a programmable level of open circuit clamping, called
voltage limited measurements (see page 70). This feature is available on
the 10 and 100 ohm ranges. The open circuit voltage can be clamped at
one of three levels, 20 mV, 100 mV, or 500 mV.
The table below shows the current and voltage levels used.
Range Test Current
Measurement
Voltage
(at Full Scale)
Open Circuit
Voltage (MV)
10 Ω
1 mA 10 mV 20, 100, or 500 mV
100 Ω
0.1 mA 10 mV 20, 100, or 500 mV
7
Chapter 7 Measurement Tutorial
Measurement Techniques and Sources of Error
261

Agilent Technologies 34420A Specifications

General

Brand	Agilent Technologies
Model	34420A
Category	Multimeter
Language	English