Measuring Inductance/Reactance and total impedance with a meter

[mull982]

Can you effectively measure the total impedance of a coil (de-energized) with a meter. The reason I ask is because the coil it made up of a toal impedance that consists of a resistive and reactive components = X + j. I know the resistive component can be measured with a meter, but can the reactive component be measured with a meter when due to the fact that it depends on frequence based on X=jwL and there is no frequency in the de-energized state.

For instance if I walk up to a coil and put my meter across it to see the toal resistance, will this be the toal impedance of this coil even when energized, and can I use this number to calculate a current draw?

 

[gar]

080709-1330 EST

mull982:

If I know the DC resistance of an inductor and I apply a DC voltage to the inductor and observe the current vs time, then the time from voltage application to the current reaching 63% of V/R is one time constant and that time equals L/R.

If you know the inductance, resistance, and frequency, then you can calculate the impedance.

Another way to measure the inductance is to put it into a tuned circuit (add a capacitor in parallel or series). If it is parallel drive it with an adjustable frequency current source, if in series a variable frequency voltage source, and use your meter to monitor for resonance.

A typical measurement method is to use LRC bridge instrument.

.