S
PECIFICATION
Power Analyzer User Manual
© Voltech 2010
Page 79
Example of Volts, Amps and Watts Accuracy Calculations
Example signals:
120V, 2.5A, 60Hz, and a power factor of 0.8, giving a Watts of 240W
Volts Accuracy
Specification: 0.1% of r 0.1% of range, +4mV + (0.02 * F)% of reading
Note: F is the frequency of measurement in kHz
Reading = 120V
Range = 215V
Frequency = 0.06kHz
Accuracy = 0.1% of 120V + 0.1% of 215V + 4mV + (0.02 * 0.06)% of 120V
= 120mV + 215mV + 4mV + 1.44mV
= 340.44mV or 0.284% of signal.
Current Accuracy
Specification: 0.1% of r 0.1% of range, +1mA + (0.02 * F)% of reading
Note: F is the frequency of measurement in kHz
Reading = 2.5A
Range = 6.25A
Frequency = 0.06kHz
Accuracy
= 0.1% of 2.5A + 0.1% of 6.25A + 1mA + (0.02 * 0.06)% of 2.5A
= 2.5mA + 6.25mA + 1mA + 0.03mA
= 9.78mA or 0.39% of signal.
