Keysight Truevolt Series Operating And Service Manual page 72

Features and Functions
For the RTD 2w probe type, an additional Auto Zero setting is available:
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 following
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 dis-
abled (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
integration time. ( There is no autozero setting for 4-wire measurements.)
For the Thermis2w or Thermis4w Probe Type...
The Thermis2w or Thermis4w probe types allow you to enable/disable low power mode:
Low Power : Disables (Off) or enables (On) low power measurements. 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 probe.
Press Done to return to the main temperature menu. For the Thermis2w probe type, an additional Auto
Zero setting is available:
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 following
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 dis-
abled (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
integration time. ( There is no autozero setting for 4-wire measurements.)
Thermistor Requirements
The DMM converts the measured thermistor resistance to temperature using the Steinhart-Hart ther-
mistor equation:
3
1⁄T = A + B (Ln(R)) + C (Ln(R))
Where:
Keysight True volt Series Operating and Service Guide 73