Making High-Speed Dc And Resistance Measurements - Agilent Technologies 34410A User Manual

Measurement Tutorial 4
For ac voltage, additional settling time may be required when the dc level
varies from sample to sample. The default sample delays allow for a dc
level change of 3% of range for all filters. If the dc level change exceeds
these levels, additional settling time is required. The multimeter's dc
blocking circuitry has a settling time constant of 0.2 seconds. This settling
time only affects measurement accuracy when dc offset levels vary from
sample to sample. If maximum measurement speed is desired in a
scanning system, you may want to add an external dc blocking circuit to
those channels with significant dc voltages present. This circuit can be as
simple as a resistor and a capacitor.
For ac current, additional settling time is not required when the dc level
varies sample to sample.
Making High Speed dc and Resistance Measurements
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The multimeter incorporates an automatic zero measurement procedure
(autozero) to eliminate internal thermal EMF and bias current errors. Each
measurement actually consists of a measurement of the input terminals
followed by a measurement of the internal offset voltage. The internal
offset voltage error is subtracted from the input for improved accuracy.
This compensates for offset voltage changes due to temperature. For
maximum reading speed, turn autozero off. This will more than double
your reading speeds for dc voltage, resistance, and dc current functions.
Autozero does not apply to other measurement functions.
34410A/11A User's Guide 115