How to Measure Inductance of a Coil
- 1). Connect a resistor of known resistance and the coil in series with the sine wave oscilloscope.
- 2). Turn on the oscilloscope and clamp the two clips of one voltmeter to the circuit on opposite sides of the coil to determine the voltage drop across the coil. Then do the same for the resistor with another voltmeter.
- 3). Set the frequency of the oscilloscope such that the voltage drop across the resistor and inductor are the same. Finding said frequency may be a matter of trial and error. At that frequency, the resistance of the resistor and the impedance of the inductor will be equal.
- 4). Set the resistor's resistance and the inductor's impedance equal to each other and solve for the inductance of the coil. Resistance = 2πfL, where "f" is the frequency of the oscilloscope and "L" is the coil's inductance. The resistance of the resistor has not changed from the start; it is independent of the frequency. So "L" can be solved for by arithmetic.
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