Meaning of effective values in a multimeter
For alternating current, its voltage is a changing waveform, and its voltage value is usually described as its effective value. For example, the 220V power supply has a peak voltage of more than 310 volts and a peak-to-peak value of more than 600 volts.
Meaning of effective values in a multimeter
1. Effective value: defined by heat generation (power), a certain alternating current generates heat through a resistor and another direct current passes through the resistor. If the heat generated in the same time is equal, then the DC voltage value is this alternating current. RMS value of the voltage.
2. True RMS: The definition of RMS is defined by heat generation, but it is difficult to measure RMS voltage in measuring instruments by this method, so most voltage measuring instruments, such as multimeters, measure voltage, The measurement method is not based on the "heating" defined by the RMS. One type of multimeter uses a sine wave as a reference, and obtains the RMS (or Derived from the average value), the effective value obtained by this method is only correct for AC voltages such as sinusoidal waveforms, and there will be deviations for waveforms of other shapes.
The voltage value of another type of multimeter is calculated by the square of the RMS value of the DC component, the fundamental wave and each higher harmonic. This value is similar to the definition of the RMS value, and there is no requirement for the shape of the waveform. The difference between the sine wave and the RMS instrument is called "true RMS" in the measuring instrument.
3. Root mean square value: Another name for the effective value (should be the true effective value on the measuring instrument).
