3-13
IM WT5000-01EN
Frequency Filter (Freq Filter)
Turning the Frequency Filter On and Off (Freq Filter)
Because the frequency filter is inserted as shown in the following figure, it affects frequency measurement (see
the block diagram in appendix 11 of the Getting Started Guide, IM WT5000−03EN).
Voltage/
current input
Normal measurement
Harmonic measurement
Frequency measurement
Line filter
(1 MHz)
Frequency
filter
Moreover, if the computing method is sync source period average, it affects the detection of the measurement
period for voltage, current, and power measurement. In this case, the frequency filter functions as a filter for
detecting the
of the sync source signal more accurately. The frequency filter is not inserted in normal
measurement or harmonic measurement. Therefore, the measured values include high frequency components
even when the frequency filter is turned on.
• This instrument detects the cross point with a hysteresis of approximately 5% of the measurement range.
• The frequency filter setting (off, or the cutoff frequency when set to on) is shown on the Elements tab of the
input information area.
• Even when the frequency filter is off, if the line filter (1 MHz) described earlier is on, the line filter (1 MHz) will
affect frequency measurement.
• We recommend that the frequency filter be turned on and the cutoff frequency set as follows according to the
input signal frequency.
Input Signal Frequency Cutoff Frequency of the Frequency Filter
100 Hz or less
0.1 kHz
1 kHz or less
1 kHz
100 kHz or less
100 kHz
Cutoff Frequency (CutOff)
Set the cutoff frequency in the following range.
0.1 kHz to 100.0 kHz (in 0.1kHz steps)
3 Input Settings (Basic Measurement Conditions)