can multimeter AC mode measure audio frequency voltage?

[loop123]

Is a multimeter in AC mode able to measure only 60Hz or 50Hz power line voltage?  Does it have a brick wall frequency filter such that it can only measure 60Hz or 50Hz? If not, what if the signal is audio range 20hz to 20000Hz. How do you compute how the measurement would be off when other frequencies are used?

Also for AC mode. Does it only measure higher voltage? In the following video, the source is 80mV 50Hz. why do the measurement results jump up and down in values?

https://www.youtube.com/shorts/VU0DDpj5_04?feature=share

[bdunham7]

The answers to all your questions depend on which meter you have and that information is found in the specifications.  Some meters won't measure accurately above 400Hz and others work fine to 100kHz or more.  Some meters don't have lower AC ranges, there's one where the lowest range is 200VAC and it has 2000 counts.  However, if your meter has a 400mVAC range it should indicate 80mVAC without any problems--so I don't know what is going on in your video.

[loop123]

The answers to all your questions depend on which meter you have and that information is found in the specifications.  Some meters won't measure accurately above 400Hz and others work fine to 100kHz or more.  Some meters don't have lower AC ranges, there's one where the lowest range is 200VAC and it has 2000 counts.  However, if your meter has a 400mVAC range it should indicate 80mVAC without any problems--so I don't know what is going on in your video.

That's great idea, to check the manual. Good I still found the 20 year old manual. What kind of signal source or even defect can usually make the values jump up and down like in the video in last message?  It's a 80mV 50H sine wave source. Btw.. if the source is 110V or 220V AC, the display is steady and doesn't jump.

[bdunham7]

What kind of signal source or even defect can usually make the values jump up and down like in the video in last message?  It's a 80mV 50H sine wave source. Btw.. if the source is 110V or 220V AC, the display is steady and doesn't jump.

Typically noise, either in the signal or internal to the meter somehow.  What is the source for the 80mVAC?

[vk6zgo]

I've only used an early Beckman & a Fluke 77 to verify that the local audio generator and level meter at a few Radio & TV sites, were correct at 0dBm----obviously not as a standard, but it would show that the audio tones were in the "ball park"or not.
 
Both DMMs read around 0.774v with 440Hz or 1kHz into a 600 ohm termination (as did an AVO model ---near enough!

I never tried them for tones above those frequencies----the Fluke didn't like 15.625 kHz TV horizontal frequency in the least, when I tried to look at that.

As far as the 80mV at 50Hz is concerned, there is the definite possibility of stray pickup on unshielded leads.