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How to measure inductance using the universal bridge meter?

Last Update Time: 2019-01-27 15:10:38

Connect the measured inductor Lx to the “tested” end, place the toggle switch in the “inside 1 kHz” position, and place the measurement selector switch in the “L” position. Estimate the size of the inductor and select the appropriate range. According to the structure of the inductor. Select the loss ratio  switch position, the air core induction is placed in the "Q × 1" position, and the iron core induction is placed in the "D × 1" position. The high-Q inductor (such as the core inductor) should be placed in the "D × 0.01" position, and the loss balance knob should be placed at "1". Adjust the bridge sensitivity so that the meter indicator is less than the full scale.


Adjust the two reading disk first, then adjust the loss balance, until the bridge sensitivity reaches its maximum, the meter pointer points to zero or close to zero, that is, the bridge is basically balanced. Make a note of the reading of the bridge reading plate and the indication of the loss balance, according to the formula: Lx = range switch indication value * (first reading of the reading plate + second digit value) and Qx = loss ratio indication value * loss balance indication value, Find the inductance of the measured inductor and the Q value of the inductor.


For example, the range switch is 100mH, the loss override switch is “Q×1”, the first reading of the bridge reads 0.8, the second reading reads 0.085, and the loss balance indication is 2.5. Then Lx=100mH*(0.8 +0.085)=88.5mH, Qx=1*2.5=2.5. If the loss override switch is placed in the "D×1" or "D×0.01" position, the Q value is 1/D.


When the size of the inductor cannot be estimated, the measurement method is basically the same as the measurement of the unknown capacitance, but the measurement selection switch is placed at "L", the range switch is placed at 10uH, and the loss ratio is determined according to the inductance structure. Other steps are performed with reference to  capacitance.


If you want to know more, our website has product specifications for the inductors, you can go toALLICDATA ELECTRONICS LIMITED to get more information.