How to use an LCR Meter

Here we have a B&K Precision 879B LCR meter with
selectable test frequencies of 100 Hz, 120 Hz, 1 kHz, and 10 kHz. In general, for capacitance measurements, it’s most ideal
to select a low test frequency when measuring high capacitance. Here we have a 5.58 mF capacitor connected to an
879B, with test frequency set to 100 Hz. The reading stays within the accuracy specification. Now if I change the test frequency to 1 kHz, notice the
reading becomes much less accurate and starts to fluctuate more. Using a higher test frequency of 1 kHz or
10 kHz is more ideal when testing smaller capacitors. Here I have a 700 pF standard capacitor
connected with the meter set to 10kHz. Notice the reading stays within specified accuracy
showing about 700.4 pF. But now if I change the test frequency… …to 100 Hz, the reading fluctuates to about 703 pF,
making it less accurate compared to expected value. For inductance measurement, the same idea is true. Generally, inductors below 2mH should be measured at 1 kHz
frequency while inductors above 200 H should be measured at 120 Hz. Choosing the right measurement mode is important in
making accurate measurements. The 879B LCR meter allows… …you to set between series or parallel measurement mode. Parallel mode is used for most capacitance measurements,
but in some cases series mode is preferred. This is especially true for large capacitors. Using the same 5.58 mF capacitor we have earlier connected
to the meter at 120 Hz test frequency, notice the reading… …between series mode reading approximately
5.56 mF, and parallel mode, 5.49 mF. Results are more accurate using series mode
to measure such a large capacitor. For inductance measurement, it’s the exact
opposite where series mode is most often used. In some instances, parallel mode is preferred.

9 thoughts on “How to use an LCR Meter

  1. @ljay0778 Thank you for recognizing the quality and value of the meter used in this video. While you are correct that the electrolytic capacitor used had a rated value printed on it in micro-farads, the meter, however displays measured values over 4,000 micro-farad as milli-farads, so the video presenter was mentioning the measured capacitance value of 5.58 milli-farad.

  2. @ljay0778 I think mF would be Milli-Farad and micro-Farad would be indicated with the uF. Maybe I'm wrong but I think thats right…

  3. Before the metric system of units was in widespread use in the U.S.
    mfd was the standard way to represent microfarad. Pico farads were
    labeled mmf (micro micro farads).

  4. I am looking to buy the 879b, but I would like to understand two things about frequency. Why does this meter only go to 10khz? Your cheaper ESR meter specifies "in-circuit" specifically, but this one does not. Does the high frequency have something to do with in-circuit testing? Basically, I want the features of this meter with the ability to test for bad capacitors without removing them.

  5. Can you Please tell me how do I measure the L/R ratio and electrostatic noide rejection ratio of a twisted pair cable

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