How to use properly DMM - dB mode?

[001]

Hi

It may be stupid question
But tell me please how I can measure audio levels with DMM

Thanx

[Conrad Hoffman]

dB always implies a reference voltage or power. If your meter has a dB scale, it will either default to some value, say 1 mW and 600 ohms (use ohms law to see what voltage that is), or it will let you zero the meter at a specific value. For those, you might decide 1 Vrms is the reference level. You set the signal to that level and hit the zero button. Then the meter reads everything in dB, above or below that level. Voltmeters will use the voltage form of dB, 20*Log(E1/E2).

[GeoffreyF]

You can look up what a decibel is.