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IM WT1801-01EN
1 Items That This Instrument Can Measure
The items that you can measure with this instrument are listed below. For details about how the values of the
measurement functions are determined, see appendix 1 in the getting started guide, IM WT1801-03EN. For
explanations of the terms measurement function, input element, and wiring unit, see “What Is a Measurement
Function?”
The input elements and wiring units referred to in each measurement function table are listed below. However,
the input elements and wiring units that you can measure vary depending on how many input elements are
installed in the WT1800.
•
Input elements:
Element1, Element2, Element3, Element4, Element5, Element6
• Wiring units: ΣA,
ΣB, ΣC
Measurement Functions Used in Normal Measurement
Voltage
Function Description Input Element Wiring Unit
Urms True rms voltage Yes Yes
Umn Rectified mean voltage calibrated to
the rms value
Yes Yes
Udc Simple voltage average Yes Yes
Urmn Rectified mean voltage Yes Yes
Uac AC voltage component Yes Yes
U+pk Maximum voltage Yes No
U−pk Minimum voltage Yes No
CfU Voltage crest factor Yes No
Current
Function Description Input Element Wiring Unit
Irms True rms current Yes Yes
Imn Rectified mean current calibrated to the
rms value
Yes Yes
Idc Simple current average Yes Yes
Irmn Rectified mean current Yes Yes
Iac AC current component Yes Yes
I+pk Maximum current Yes No
I−pk Minimum current Yes No
CfI Current crest factor Yes No
Power
Function Description Input Element Wiring Unit
P Active power Yes Yes
S Apparent power Yes Yes
Q Reactive power Yes Yes
λ
Power factor Yes Yes
Φ
Phase difference Yes Yes
Pc Corrected Power Yes Yes
P+pk Maximum power Yes No
P−pk Minimum power Yes No
Frequency
Function Description Input Element Wiring Unit
fU Voltage frequency Yes No
fI Current frequency Yes No
fPLL1 Frequency of PLL1
1
No No
fPLL2 Frequency of PLL2
2
No No
1 On models with the harmonic measurement option or the simultaneous dual harmonic measurement
option.
2 Only on models with the simultaneous dual harmonic meas
urement option.