Measurement Fundamentals - Agilent Technologies 34972A User Manual

Measurement Fundamentals

This section explains how the 34970A/34972A makes measurements and
discusses the most common sources of error related to these
measurements.
The Internal DMM
The internal DMM provides a universal input front-end for measuring a
variety of transducer types without the need for additional external
signal conditioning. The internal DMM includes signal conditioning,
amplification (or attenuation), and a high resolution (up to 22 bits)
analog-to-digital converter. A simplified diagram of the internal DMM is
shown below. For complete details on the operation of the internal DMM,
refer to "Measurement Input" on page 74.
Analog
Signal
Input
Conditioning
Signal
The internal DMM can directly make the following types of
measurements. Each of these measurements is described in the following
sections of this chapter.
• 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)
Measurement Fundamentals
Analog to
Digital
Amp
Converter
Chapter 7 Tutorial
To/From
Earth
Main
Referenced
Processor
Section
= Optical Isolators
265
4
7