True Rms Ac Measurement - Hantek HDM3000 User Manual

shown.
Press Null. The multimeter saves the test lead resistance as the null value of the 2-wire
resistance and subtracts this value from future measurements.
Minimize the power impact
When measuring resistors for temperature measurement (or resistors with large
temperature coefficients, be aware that the multimeter will dissipate some power on the
device under test.
If power consumption is a problem, a higher fixed range should be chosen (all multimeter
models). In low power mode, the test current applied for each measurement range for the
standard resistance measurement is less than the normally applied test current to reduce
power consumption and self-heating in the DUT.

True RMS AC measurement

The AC measurement of HDM3000 has true RMS response. The average heating
power of a resistor over a period of time is proportional to the square of the effective value
of the voltage applied to the resistor over that period of time, have nothing to do with the
waveform. If the energy outside the effective bandwidth of the multimeter is negligible in
The
the voltage or current waveform, the HDM3000 can accurately measure its RMS.
HDM3000 has an effective AC voltage bandwidth of 300 kHz and an effective AC
current bandwidth of 10 kHz.
The AC voltage and AC current functions of the multimeter measure "AC coupling" true
RMS, i.e., the RMS of the measured AC component of the signal (the DC component is
filtered out). As shown in the table below, since sine, triangular, and square waves (50%
duty cycle) do not contain a DC offset, their AC RMS are equal to AC+DC RMS.
Table: True RMS AC measurement of sine wave, triangle wave and square wave
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