Multimeter measures either peak voltage or rms voltage?

Question

Multimeter measures either peak voltage or rms voltage?

Answer 1

What you can read on the display is just the rms value; be careful if you use a cheap instrument in case of distorted waveshapes..displaied values could be far from the true rms value...just costy devices , such as Fluke, can compensate harmonic effect on measured value...

Answer 2

None of this makes a lot of sense, but I'll try. The meter won't 'blow up' if misused, but you can burn out a resistor or blow an internal fuse if you make a big enough mistake. It seems that they're telling you to not use the meter on any power lines that are rated over 500 volts AC. For one thing, the meter isn't rated for work around power lines of those voltages, and you'll go over the meter's capacity as well. When the meter is set on its continuity and resistance functions, it is not meant to be used on an energized circuit. Apparently this particular meter has been strengthened in some way so it won't be damaged if there's momentary contact with an energized circuit, but they're telling you not to push it: 250v for 15 seconds, maximum, but you shouldn't even be doing that. That last one seems to be telling you much the same thing: on the 200 mV range, which means 0.2 volts, please do not apply some huge voltage. However, the numbers don't make much sense: 600V ac and 200 volts rms are not equivalent. Now, I don't know if these are at all correct. You may be running into poor labels or poor instructions, both of which are common enough. If there is a current-measuring function--you haven't said that there is--you must be very careful not to apply a voltage source across the leads when the meter is set to measure current. Mostly, however, you won't be using that function. I wish I could recommend a decent book on the subject of multimeter use, but I haven't done any sort of a search for some thirty years. If you're using it for automotive work, some car manuals have a meter tutorial in them.

Answer 3

This Site Might Help You.



RE:

Multimeter measures either peak voltage or rms voltage?

Answer 4

Peak Voltage Tester

Answer 5

Depends on the meter. But they will all display the RMS value of a sine wave.



The cheaper ones measure either peak voltage or half-wave-rectified average voltage but are calibrated to display RMS voltage. They are only accurate for a sine wave input.



Better ones, labeled "true RMS" will actually read and display the RMS value of the signal and are accurate for sine waves as well as other waveforms.





Be careful of terminology. Display is different from measure. The ones that measure peak average value, for example, multiply that voltage by a constant so that the display shows the equivalent RMS value.

Answer 6

The inexpensive analog moving-needle meters you can get at hardware stores and Radio Shack measure average current, and thus average voltage. They are calibrated to read as RMS voltage, but that calibration is true only in a very small frequency band, 50 Hz to 60 Hz. You cannot measure the voltage coming out of an audio amplifier with them.



Digital meters can be designed to display anything.



You have to read the specification sheets to know for sure.



http://www.myflukestore.com/p1228/fluke_179.php

For example, the Fluke 170-series of digital meters have this specification:

Voltage frequency is specified from 2 Hz to 100 kHz.

Current Frequency is specified from 2 Hz to 30 kHz.



Inexpensive digital meters only work with 50 Hz to 60 Hz voltages and currents.



Most electrician and industrial digital multimenters are designed for the 50 Hz to 60 Hz range.



Take a look at the Fluke website and explore looking for the specifications and data sheets.



For example, on this webpage http://www.myflukestore.com/p3716/fluke_117.php

look for the tab "Documents" and you can download a lot of very informative PDF files.

Answer 7

generally they measure rms value .Its not convinent to meausre peak voltage beacause it give no idea about voltage at any instance so rather than peak multimeter measure average A.C current called rms voltage

Answer 8

Common AC volt meter measures AC Vrms value.

Special type AC volt meter can measure AC Vp value.

Answer 9

Rms value, if I remember right