User`s guide

74
Chapter 3 System Overview
Measurement Input
Measurement Input
The 34970A/34972A allows you to combine a DMM (either internal or
external) with multiplexer channels to create a scan. During a scan, the
instrument connects the DMM to the configured multiplexer channels
one at a time and makes a measurement on each channel.
Any channel that can be “read” by the instrument can also be included in
a scan. This includes any combination of temperature, voltage,
resistance, current, frequency, or period measurements on multiplexer
channels. A scan can also include a read of a digital port or a read of the
totalizer count on the multifunction module.
The Internal DMM
A transducer or sensor converts a physical quantity being measured into
an electrical signal which can be measured by the internal DMM. To
make these measurements, the internal DMM incorporates the following
functions:
• Temperature (thermocouple, RTD, and thermistor)
• Voltage (dc and ac up to 300V)
• Resistance (2-wire and 4-wire up to 100 M)
• Current (DC and AC up to 1A)
• Frequency and Period (up to 300 kHz)
34970A Refresh UG.book Page 74 Wednesday, February 17, 2010 12:34 PM