7-6
IM WT310-02EN
• Influence of self-generated heat caused by voltage input
Add 0.0000001 ×U
2
% of reading to the AC voltage accuracies.
Add 0.0000001 ×U
2
% of r 0.0000001 ×U
2
% of range to the DC current accuracies. U is
the voltage reading (V).
Influence of self-generated heat caused by voltage input lasts until falling the temperature of the
input resistor even if voltage input decreases.
• Influence of self-generated heat caused by current input
WT310:
Add 0.00013 × I
2
% of reading to the AC current accuracies.
Add 0.00013 × I
2
% of r 0.004 × I
2
mA (0.5 A, 1 A, 2 A, 5 A, 10 A, and 20 A ranges) or
0.00013 × I
2
% of r 0.00004 × I
2
mA (5 mA, 10 mA, 20 mA, 50 mA, 100 mA, and 200
mA ranges) to the DC current accuracies.
I is the current reading (A).
WT310HC:
Add 0.00006× I
2
% of reading to the AC current accuracies.
Add 0.00006 × I
2
% of r 0.001 × I
2
mA to the DC current accuracies.
I is the current reading (A).
WT332/WT333:
Add 0.00013 × I
2
% of reading to the AC current accuracies.
Add 0.00013 × I
2
% of r 0.002 × I
2
mA to the DC current accuracies.
I is the current reading (A).
Influence of self-generated heat caused by current input lasts until falling the temperature of the
shunt resistor even if current input decreases.
• Accuracy changes caused by data update interval
When the data update interval is 100 ms, add 0.05% of reading to the 0.5 Hz to 1 kHz
accuracies.
• Guaranteed accuracy ranges for frequency, voltage, and current (direct input)
All accuracy figures for 0.5 Hz to 10 Hz are reference values.
The current accuracy figures for DC, 10 Hz to 45 Hz, and 400 Hz to 30 kHz when the
current exceeds 20 A are reference values.
WT310 only
The maximum current input is 6 A when the frequency is over 30 kHz up to 100 kHz.
Input range
1 to 130% with respect to the rated range of voltage or current. (It displays up to 140%.)
(Add the reading error × 0.5 to above accuracies for the range of 110% to 130% of the rated
range.)
WT310HC: 40 A Range Only 1 to 100% (display is 110%)
The synchronization source level must meet the frequency measurement input signal level.
Measurement frequency
range
Data update interval
Measurement Frequency Range
0.1 s
DC, 25 Hz ≤ f ≤ 100 kHz
0.25 s
DC, 10 Hz ≤ f ≤ 100 kHz
0.5 s
DC, 5 Hz ≤ f ≤ 100 kHz
1 s
DC, 2.5 Hz ≤ f ≤ 100 kHz
2 s
DC, 1.5 Hz ≤ f ≤ 100 kHz
5 s
DC, 0.5 Hz ≤ f ≤ 100 kHz
Only for direct current input of WT310HC, the maximum measurement range is 20kHz.
When the line filter is turned
ON
45 to 66 Hz: Add 0.2% of reading.
Less than 45 Hz: Add 0.5% of reading.
Temperature coefficient
Add ±0.03% of reading/°C within the range of 5 to 18°C or 28 to 40°C.
Accuracy when the crest
factor is set to 6
Accuracy obtained by doubling the measurement range error for the accuracy when the crest factor
is set to 3.
7.3 Accuracy
