HP 34970A manual 105

Chapter 4 Features and Functions

General Measurement Configuration

U

When autozero is xtuxw (default), the instrument internally disconnects the input signal following each measurement, and takes a

tw”z . It then subtracts the zero reading from the preceding reading. This prevents offset voltages present on the instrument’s input circuitry from affecting measurement accuracy.

When autozero is w”uw , the instrument takes one zero reading and subtracts it from all subsequent measurements. It takes a new zero reading each time you change the function, range, or integration time.

∙Applies to temperature, dc voltage, 2-wire ohms, and dc current measurements only. Autozero is enabled when you select 4-wire ohms measurements.

∙ The autozero mode is set indirectly when you set the resolution and 4

integration time. Autozero is automatically turned off when you select an integration time less than 1 PLC.

∙You can set autozero from the remote interface only; you cannot directly set autozero from the front panel.

∙ The autozero setting is stored in t”memory, and wx change when power has been off, after a Factory Reset (*RST command), or after an Instrument Preset (SYSTem:PRESet command).

∙exx Vxytvx bxt”: The OFF and ONCE parameters have a

similar effect. Autozero OFF wx issue a new zero measurement. Autozero ONCE issues an immediate zero measurement.

ZERO:AUTO {OFFONCEON}[,(@<v“r >)]

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