Functions - YOKOGAWA WT200 User Manual

1.2

Functions

Input Functions
Display Functions
Peak Measurement Function
MAX Hold Function
Computing Functions
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Voltage and Current Input Sections
A voltage or current supplied to each input terminal is normalized then sent to the A/D
converter, where the voltage or current is converted into digital signals. The digital
signals are then sent via photo-isolator to a 16-bits high-speed DSP (Digital Signal
Processor) or CPU, where computation of the measured value is carried out.
Frequency Measuring Range
Measurement of DC voltage, current and power as well as AC voltage and current in
the frequency range 10 Hz to 50 kHz.
Filter
This instrument carries out various measurements after synchronizing the frequency of
the input signals. Therefore, correct measurements are necessary. Thus, a filter is
being applied to the frequency measurement circuit to eliminate noise of waveforms,
such as inverted and distortion waveforms.
Wiring Method
The wiring method indicates the circuit configuration used to measure the voltage,
current, and power. The WT200 uses a single-phase, two-wire (1φ2W) wiring method.
This function enables display of measured/computed values using three red high-
intensity 7-segment LED displays. A total of three values can be displayed at once.
This function measures the peak values of the voltage and current. This value is used
to compute the crest factor.
This function holds the maximum values of the voltage, current, active power, apparent
power, reactive power, voltage peak, and current peak. It holds the maximum value
that exists while the MAX hold function is enabled.
Apparent Power, Reactive Power, Power Factor and Phase Angle
Based on the measurement values of voltage, current and active power, the values of
apparent power, reactive power, power factor and phase angle can be computed.
Scaling
When performing voltage or current measurements with an external PT, CT, shunt,
external sensor (clamp) or such connected, you can set a scaling factor to the primary/
secondary ratio. This is called scaling. This function enables display of the measured
values of voltage, current, active power, reactive power, integrated current and
integrated power factor in terms of primary-side values.
Averaging
This function is used to perform exponential or moving averaging on the measured
values before displaying them in cases where the measured values are not stable.
Four Arithmetic Operation
Results from six types of arithmetic operations can be displayed. (A+B, A–B, A
2 2
A /B, A/B )
Crest Factor
This function determines the crest factor of the voltage and current using peak and
RMS values.
B, A/B,
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IM 253421-01E