LCR readings need their measurement conditions

Record the conditions before the number

The blank LCR record keeps these fields beside the reading. It deliberately contains no example measurements.

Prepare a safe, repeatable fixture

Disconnect power and discharge the component using an appropriate procedure; verify the absence of stored voltage before connecting an LCR meter. Do not discharge a capacitor through the meter. In-circuit tests include other paths, so isolate a lead or remove the component when the question requires its individual value.

1. Choose the fixture appropriate to the instrument. A supported four-terminal-pair or Kelvin arrangement can reduce particular lead errors; ordinary clips do not acquire those properties by name.
2. Perform the documented open and short compensation at the measurement plane. Keep lead spacing and geometry consistent with the test.
3. Select a frequency and signal level compatible with the component specification and instrument range.
4. Choose and record the series or parallel model; repeat after reseating to check contact sensitivity.

Compensation is not traceable calibration. If the meter provides no selectable level or bias, record that limitation rather than assuming another instrument’s setting.

ESR, DCR and capacitance answer different questions

ESR is an equivalent AC loss term at a stated frequency. DCR is a DC resistance measurement. Neither alone establishes capacitor leakage at operating voltage, insulation integrity or remaining service life. An in-circuit low ESR reading can belong to another capacitor in parallel.

For a simple series capacitor model, D = 2πfC × ESR and Q = 1 / D. These relations apply to that model at that frequency; do not mix a parallel-model capacitance with an unrelated ESR reading. Inductor core loss, saturation and self-resonance can also make a single low-level inductance value a poor predictor of operating behaviour.

When two meters disagree

First match frequency, level, model, bias and fixture. Compare against a stable component with a documented tolerance and, where needed, a calibrated reference or external calibration service. A disagreement is not automatically an error in the cheaper meter; both instruments may be measuring different conditions.

Save both readings with uncertainties or known limitations, and avoid “percentage accuracy” claims without a justified reference. Next use the measurement record method to separate the component observation from the diagnosis. The cited LCX200 review uses capabilities and equipment that a basic handheld meter may not provide.