Keysight Truevolt Series Operating And Service Manual page 66

Features and Functions
Step 4: Press Range to select a range for the measurement. ( Auto (autorange) automatically selects the
range for the measurement based on the input. Autoranging is convenient, but it results in slower meas-
urements than using a manual range. Autoranging goes up a range at 120% of the present range, and
down a range below 10% of the present range. Press More to switch between the two pages of settings.
Notice the amount of test current sourced is shown for each range. After selecting a range, the main res-
istance menu is displayed.
Step 5: Auto Zero : Autozero provides the most accurate measurements, but requires additional time to
perform the zero measurement.With autozero enabled (On), the DMM internally measures the offset fol-
lowing each measurement. It then subtracts that measurement from the preceding reading. This prevents
offset voltages present on the DMM's input circuitry from affecting measurement accuracy. With autozero
disabled (Off), the DMM measures the offset once and subtracts the offset from all subsequent meas-
urements. The DMM takes a new offset measurement each time you change the function, range, or integ-
ration time. ( There is no autozero setting for 4-wire measurements.)
Step 6: OffstComp (34465A/70A only): Enables or disables offset compensation. Offset compensation
removes the effects of small dc voltages in the circuit being measured. The technique involves taking the
difference between two resistance measurements, one with the current source set to the normal value,
and one with the current source set to a lower value. Enabling Offset Compensation approximately
doubles the reading time.
Step 7: Low Power (34465A/70A only):The low power mode sources less test current per measurement
range than is normally sourced for standard resistance measurements, to reduce power dissipation and
self-heating in the DUT. With low power On, pressing Range displays the lower current sourced for each
range:
Low-power resistance measurements apply to the 100Ω through 100kΩ ranges only. The 1 MΩ through 1
GΩ ranges source the same current regardless of the low-power setting.
Keysight True volt Series Operating and Service Guide 67