Waveform Graph/FFT

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Manual

Simple oscilloscope function and FFT conversion

Ideal when reviewing waveforms while investigating the cause of a power supply problem.
Display waveforms like an oscilloscope.
Display motor starting current waveforms.

You can display waveforms using a tester you’ve got handy.

Example uses

Recording a motor’s starting current

Record the starting current of the motor before and after the replacement work.

Features

That problem... It may be caused by a distorted waveform, even if the measured values are normal.

Waveforms can be distorted, even if measured values are normal. Distorted waveforms sometimes cause electric devices to malfunction.

By measuring waveforms instead of making judgments based on measured values alone, you can realize higher-quality measurement.

Measurable waveform frequencies and measurement time vary by instrument. For example, if you measure a 60 Hz sine wave using the CM4371-50 or CM4373-50, the app will display a waveform covering 3 cycles.

Since the CM4371-50 and CM4373-50 have a measurement time of 50 ms, you can display 3 cycles of a 60 Hz waveform.

Freedom for waveform operations

The display can be switched among three modes: simultaneous measured value and waveform display, waveform display, and measured value display.

The display is refreshed at an interval of approximately 1 s.

You can pinch in and out on the waveform to zoom in and out.

You can zoom in or out on the waveform with simple operations.

FFT conversion: See how distorted a waveform is.

You can perform FFT conversion on measured waveforms so that you can view individual frequency components.

You can also display total harmonic distortion (THD) and crest factor (CF).

*This simplified FFT conversion process does not take calculation error into account.

Display FFT conversion results with a single tap.

There’s also a harmonic analysis function in case you wish to review harmonics more closely. You can also acquire logging data for harmonic components.

More information about the harmonic analysis function

Checking motor starting current waveforms

Using an instrument that has an INRUSH (inrush current) function, you can measure a motor’s starting current.

You can then review that waveform using GENNCT Cross.

AC/DC Clamp Meter CM4371-50, CM4372, CM4373-50, CM4374, CM4375-50, or CM4376 AC Clamp Meter CM4141-50, CM4142 AC Leakage Clamp Meter CM4002 or CM4003

Two waveforms measured using the in-rush current function can be saved in the instrument’s memory, and those waveforms can be displayed by GENNECT Cross.

** AC Leakage Clamp Meter CM4001**

Functionality is not available for saving data on the instrument. While the instrument is waiting for an inrush current, GENNECT Cross will be in standby mode and will not display a waveform. When an inrush current is measured, that waveform will be displayed.

You can display the magnitude, peak value, and waveform for inrush currents.

Instructions

Waveform display/FFT function operating manual

Specifications

No. of instrument connections	1
Waveform display, measured values, FFT display	Display refresh interval: Approx. 1 s. Save format: JPEG image (no waveform measured values)
Sampling frequency, sampling time	Varies by instrument. See here for details.
Inrush waveform acquisition	Acquires the inrush waveform saved on the instrument.
THD display (Total harmonic distortion, all harmonics)	Calculates THD based on the FFT results. $THD[\%]=\frac{\sqrt{\sum_{n=2}V_n^2}}{V_1}\times100$ $V_1$ : Fundamental component $V_n$ : nth harmonic component
CF display (crest factor)	Calculates CF from the measurement waveform. $C.F.=\frac{W_{max}}{\sqrt{\sum_{n=1}W_n^2}}$ $W_n$ : Amplitude value data for the measurement waveform $W_{max}$ : Crest value; Maximum amplitude value for the measurement waveform