Keysight Technologies 3458A Guide D'utilisation page 441

(omitting the resolution parameter of the DCV command and using the RES
command) both set the 3458A to DCV, the 100 V range, the integration period to
8 µs, and set the resolution to .001% of 20 V. The reading rate can be doubled
simply by turning the auto zero operation off. Auto zero on (AZERO,ON) is the
default condition of the 3458A. In this condition, to eliminate any thermally
generated offset voltage on the input of the 3458A, internally, the input is shorted
and a measurement is made to establish the offset voltage. The measured DC
offset is subtracted from the actual input voltage and presented to the output as
the final answer. Hence, there are really two measurement cycles normally
involved in one measurement. This procedure ensures the specified accuracy of
the 3458A, but it can produce measurements only half as fast as just measuring
the input voltage. In a thermally stable environment, very little reduction in
accuracy over a short period of time (10 minutes or so) results from disabling this
function. Hence, beyond reducing the integration period, AZERO OFF is the most
significant command you may use to increase reading rate.
DC current
The same general discussion for measuring DCV applies to current. With the
exception that the current input is a separate terminal, the command DCI is used
the same way that DCV is used. The current measurement path is selected with a
series armature relay instead of the faster reed relays of DC volts and Ohms;
hence, switching between current and other functions will take more time (in the
neighborhood of 30 to 40 ms) than between DCV and Ohms.
Resistance
Resistance measurements require more settling time than DCV measurements.
Above 10 kW longer settling time is introduced to make sure that the first reading
is correct within specified limits. Again, if you wish to compromise the accuracy of
the first reading, the settling time associated with the higher resistance
measurements may be defeated by using the default delay. Before you change the
program's delay setting to a lesser value, experiment with the application to
determine the optimum settling time.
increasing settling times as a function of increasing resistance for first reading
right.
Keysight 3458A User's Guide
Optimizing Throughout and Reading Rate
Figure D-2 shows the general trend in
D
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