Audio Science Review of Expert 200.

[Jean-Marie]

For digital multi-meters, there is an ADC involved. Now to read the RMS value of an AC signal, you have the choice between two options: either you sample with a high enough frequency to be able to do the calculation in the digital domain, or you use a electrical circuit that does the integration for you and read the outcome of that circuit.

Such a circuit it typically act as low pass filter with -20dB per decade and therefore is only accurate around the frequency it is designed for.

If I were to design a multi-meter I would center my design around 55Hz to cope both the 50Hz and 60Hz AC you can encounter.

10kHz would be more that two decades past 55Hz, therefore I doubt the readings would be really meaningful.

On the other hand if I was doing it in the digital domain, typical integration in the digital domain need at minimum 4 times the sampling frequency as the higher signal they integrate.
That would mean 240Hz for an 60Hz AC signal and 60kHz sampling rate for a 15kHz signal.
Unless this is a very expensive meter, I doubt that anyone would have a design at 60kHz then a design at 240Hz would do the job.

My two cents.... for the moment.