watt meter

[domnic]

if use a true rms ammeter and a true rms volt meter can you use thes two in place of a watt meter.

 

[charlie b]

Re: watt meter

I think not. Watts will be equal to amps times volts times the power factor. A wattmeter will be able to detect the phase angle between amps and volts, and calculate the power factor (it is the cosine of that angle). With the two meters you named, you will not know the phase angle, and therefore will not know the power factor.