B&K Precision BC 885 AC Adapter for LCR/ESR Meter, 120V

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