YOKOGAWA WT1800 User Manual page 92

6.4 Accuracy
Power
Item
Accuracy (at 6 months)
• For the external current sensor range, add the following values to the accuracies listed above:
DC current accuracy: 50 μV
DC power accuracy: (50 μV/rated value of the external current sensor range) × 100% of range
• For the direct current input range, add the following values to the accuracies listed above:
50 A input elements:
DC current accuracy: 1 mA
DC power accuracy: (1 mA/rated value of the direct current input range) × 100% of range
5 A input elements:
DC current accuracy: 10 μA
DC power accuracy: (10 μA/rated value of the direct current input range) × 100% of range
• For the accuracies of waveform display data functions Upk and Ipk:
Add the following values (reference values) to the accuracies listed above. The effective input range is within ±300% (±600%
when the crest factor is set to 6) of the range.
Voltage input: {1.5 × √(15/range) + 0.5}% of range
Direct current input range:
50 A input element: 3 × √(1/range)% of range + 10 mA
5 A input element: {10 × √(10m/range) + 0.5}% of range
External current sensor input range:
50 mV to 200 mV range: {10 × √(0.01/range) + 0.5}% of range
500 mV to 10 V range: {10 × √(0.05/range) + 0.5}% of range
• Influence of temperature changes after zero-level compensation or range change
Add the following values to the accuracies listed above.
DC voltage accuracy: 0.02% of range/°C
Direct current input DC accuracy
50 A input element: 1 mA/°C
5 A input element: 10 μA/°C
External current sensor input DC accuracy: 50 μV/°C
DC power accuracy: the product of the voltage influence and the current influence
• Influence of self-generated heat caused by voltage input
Add the following values to the voltage and power accuracies:
AC input signal: 0.0000001 × U
DC input signal: 0.0000001 × U
U is the voltage reading (V).
Even if the voltage input decreases, the influence from self-generated heat continues until the temperature of the input resistor
decreases.
• Influence of self-generated heat caused by current input
Add the following values to the current and power accuracies of 50 A input elements.
AC input signal: 0.00006 × I
DC input signal: 0.00006 × I
6-8
Specifications
Conditions
Same as the conditions for the voltage and current accuracies
Frequency
DC
0.1 Hz ≤ f < 10 Hz
10 Hz ≤ f < 45 Hz
45 Hz ≤ f ≤ 66 Hz
66 Hz < f ≤ 1 kHz
1 kHz < f ≤ 50 kHz
50 kHz < f ≤ 100 kHz
100 kHz < f ≤ 200 kHz
200 kHz < f ≤ 500 kHz
500 kHz < f ≤ 1 MHz
2
% of reading
2
% of reading + 0.0000001 × U
2
% of reading
2
% of reading + 0.004 × I
Accuracy
±(reading error + measurement range error)
±(0.05% of reading + 0.1% of range)
±(0.3% of reading + 0.2% of range)
±(0.1% of reading + 0.2% of range)
±(0.1% of reading + 0.05% of range)
±(0.2% of reading + 0.1% of range)
±(0.3% of reading + 0.2% of range)
50 mV, 100 mV, or 200 mV range of an external current sensor's input
±(0.5% of reading + 0.2% of range)
Direct input of a 50 A input element
±{(0.1 × f + 0.2)% of reading + 0.2% of range}
±(0.7% of reading + 0.3% of range)
Direct input of a 50 A input element
±{(0.3 × f − 9.5)% of reading + 0.3% of range}
±{(0.0105 × f − 0.25)% of reading + 1% of range)}
Direct input of a 50 A input element
±{(0.09 × f + 11)% of reading + 1% of range}
±{(0.0105 × f − 0.25)% of reading + 1% of range)}
Direct input of a 50 A input element
Accuracy is not defined.
±{0.048 × f − 20)% of reading + 2% of range)}
Direct input of a 50 A input element
Accuracy is not defined.
2
% of range
2
mA
IM WT1801-03EN