will multimeter show peak to peak voltage or rms value when the probes of the function generator is connected?

Question

i did an expt to measure the peak to peak voltage and rms voltage using cro and checked the same using multimeter.. i want to know if the multimeter in ac mode will give the rms value or the peak to peak voltage?

Answer 1

Digital, or analogue multimeter's display the RMS value of a Sine wave which is 0.707 x peak.



However other AC wave forms that have the same positive and negative forms/values, such as Square wave, RMS = Peak, or Triangle RMS = 0.5 x Peak.



There are specialised meters, such as the "Scope Meter", which will not only display the Peak and the RMS values, but will also display the waveform simultaneously, but these are very expensive.

Answer 2

Peak To Peak To Rms

Answer 3

As others have said most meters expect to see a sine wave and will display a voltage 0.707 (= 1/√2) of the peak. However the common multimeter will not display the proper voltage of a triangle, pulse or square wave nor will they properly respond if the frequency of the sine wave is above a few hundred Hertz.

Answer 4

Peak To Peak Voltage

Answer 5

Common type multimeter was designed to read rms value. A special type meter can display peak to peak value. Check your meter specification to find out or multiplier the rms value with 2.82 to obtain Vp-p.

Answer 6

If it is a true RMS meter then it will give RMS. Most meters give average DC not RMS only a peak hold meter will give you EP and you have to double it to get EP-P. The way to really measure it is with an oscilloscope to see if the wave is distorted. Read the Manual for the meter to see what you are really measuring.

Answer 7

True rms meters give rms value. For sine rms is peak/1.414. peak to peak is 2.83 times rms value.

Some meters may give correct rms value only for sinusoids. They are called average reading rms calibrated.

In some true rms meters you may find that there is a range called ac+dc in which the rms value is sqrt(ac^2+dc^2). So if you have a 3Vrms ac added to dc of 4V, the meter will read 5V they will also have separate dc ranges and ac ranges other than this ac+dc range.

Answer 8

Most ac voltmeters measure the peak or peek to peak voltage of the ac wave form, then display 0.707 of that amount or half that if it measures peak to peak. This gives the correct RMS voltage for a sine wave, but not for other wave shapes.