arithmetic mean value vs TRMS AC+DC

[Ig_sherwood]

Maybe this question will be dumb ,but im just an hobbyst in electronic field 

So i want to ask you today if it's still good to buy an multimeter without TRMS ,only arithmetic mean value
There is a good guy ,which want to sell me an gossen metrawatt 23s and i don't know if this deal worth or not.

[helius]

It only depends if you care about the accuracy of AC measurements on non-sinusoidal signals (such as square waves or PWM signals). Some high-priced meters do not have TRMS, such as Metrahit 27: some users simply do not need it. But if you will test things like triac light dimmers, TRMS is useful to have.

[2N3055]

Also any work on audio needs TRMS... and about 100 kHz of bandwidth...

[David Hess]

Unless you already have an application which needs RMS measurements, I would not worry about it.

I actually prefer to disable RMS on my RMS meters if possible because it slows down the settling time a lot with lower signal levels; in some cases it can take 10s of seconds to settle.  I only use it when absolutely necessary which is rare.

[Ig_sherwood]

Actually im working on this project
https://www.eevblog.com/forum/projects/diy-metcal-13-56-mhz-rf-supply/

[2N3055]

Normal multimeters will not work on 13 MHz in AC mode... Most are few kHz and good ones are few 100 kHz.. For 13 MHz you'll need an oscilloscope or RF multimeter..
In practice that means you need oscilloscope...