FAQ-Power Measuring Instruments, General

Questions

Unstable measured values of voltage, current, and power.
Unstable measured value of efficiency when measuring at I/O efficiency from input power ΣA and output power ΣB to and from the instrument.
Voltage, current, and power values measured on power meter A do not match those from power meter B.
The theoretical (calculated) power value does not match the measured value.
The power, power factor, and phase angle of each input element do not match when measuring the balanced three-phase load.
When measuring the balanced three-phase load and displaying the waveform on the power meter, the phase angle of the voltage across each input element is not 120 degrees.
When measuring the balanced three-phase load, sometimes the result is a negative value.
The theoretical (calculated) three-phase apparent power values (ΣVA and ΣS) do not match the measured values. Also, the measured values from power meter A and power meter B do not match.
The theoretical (calculated) power factor and phase angle do not match the measured values.
Also, the measured values from power meter A and power meter B do not match.
When measuring a sine wave but the RMS and MEAN values are not right.
The peak value and crest factor do not match, and are not stable.
Measurements of voltage, current, and power in normal mode and harmonic mode do not match.
Measurments of inverter efficiency exceed 100%.
Measured/displayed value on the main unit does not match the DA output displayed value.
Unstable measured values of Var and ΣVar.
Why are the input terminals on the rear panel of the power meter?
Why do you use a binding post for the current terminals?