YOKOGAWA WT210, User Manual, Page: 299 / 316

16-4
IM 760401-01E
Active Power Accuracy
Item Specifications
Accuracy Requirements
Same as the conditions for voltage and current.
Accuracy (3 months after calibration)
Frequency Accuracy
(The accuracy shown below is the sum of reading and range errors.)
DC
±
(0.3% of r 0.2% of range)
0.5 Hz
≤
f < 45 Hz
±
(0.3% of r 0.2% of range)
45 Hz
≤
f
≤
66 Hz
±
(0.1% of r 0.1 % of range)
66 Hz < f
≤
1 kHz
±
(0.2% of r 0.2 % of range)
1 kHz < f
≤
10 kHz
±
(0.1% of r 0.3 % of range)
±
[{0.067
×
(f – 1)}% of reading]
10 kHz < f
≤
100 kHz
±
(0.5 % of r 0.5 % of range)
±
[{0.09
×
(f – 10)}% of reading]
* The unit of f in the read error equation is kHz.
Add
±
10
µ
A
×
voltage reading to the DC accuracy of power.
Influence of power factor When power factor (PF) = 0(VA: apparent power)
•
±
0.2% of VA for 45 Hz
≤
f
≤
66 Hz.
•
±
{(0.2 + 0.2
×
f)% of VA} for up to 100 kHz as reference data. The unit for frequency f is kHz.
When 0 < PF < 1 (
φ
: phase angle of the voltage and current)
Add the power reading
×
{tan
φ ×
(influence when PF = 0)}%.
Effect when the line filter 45 to 66 Hz: Add 0.3% of reading. Less than 45 Hz: Add 1% of reading.
is turned ON
Temperature coefficient Same as the temperature coefficient for voltage and current.
Accuracy 12 months Add
±
(reading error of the accuracy at 3 months after calibration
×
0.5)
after calibration
Accuracy when the crest Accuracy obtained by doubling the measurement range error for the accuracy when the crest factor
factor is set to 6 is set to 3.
Accuracy of Other Parameters and Computation Accuracy
• For the accuracy of frequency voltage and current, see “Frequency Measurement” in section
16.3, “Functions.”
• For the accuracy of integrated values Wh, Wh+, Wh-, Ah, Ah+, and Ah- and the integration timer,
see “Integration” in section 16.3, “Functions.”
• For the accuracy of voltage, current and power during harmonic measurement, see “Harmonic
Measurement” in section 16.3, “Functions.”
• For the D/A output accuracy, see section 16.5, “D/A Output.”
16.2 Accuracy