# Iron Core Inductor Internal Resistor Value

#### enes246

Joined Nov 30, 2016
10
Hi everyone,
How can I measure the inductor internal resistance value?
Actually, I wonder that how the applied voltage frequency effect the internal resistance of the iron core inductor.

I have an inductor ,which is designed for 50Hz supply frequency, and its value given in name plate as 3.2mH. I need the internal resistance of the this inductor. I try to measure the this value by using the Isotech LCR-819 meter. If the frequency value is 50Hz, the resistance value shown in the LCR meter screen is 0.06 ohm but if the frequency value is setted the 1kHz, resistance value shown in the LCR meter screen is 1.6 ohm. Also , if the frequency is 100 kHz, the resistance value shown in the LCR meter screen is 30 ohm. How it is possible.
The internal resistance value change with frequency?
how the frequency change the internal resistance. Iron core affect the resistance?

Thank you .

#### ericgibbs

Joined Jan 29, 2010
9,860
hi 246,
The Impedance of an Inductor is Z= 2 * pi * f * L
Using different test frequencies, will, give a different Impedance value.

Use a regular DC type Ohm meter to measure the actual Resistance of the inductor coil.
E

• enes246

#### DickCappels

Joined Aug 21, 2008
6,315
Except for the lossy shunting effects of the core which would look a lot like a resistor in parallel with the inductance.

• enes246