User`s manual

9-41

IM 701610-01E

Waveform Analysis

Entering Labels

29. Press the M1 Label soft key to display the keyboard. See section 8.5, “Setting the

Waveform Labels” for information about displaying labels.

Explanation

This function displays the power spectrum of CH1 to CH4 and Math1 (or CH1, and CH2,

and Math1 on the DL1620) waveforms.

Number of Computing Points: Point

Select 1 k or 10 k.

If the record is longer than the total number of computing points, the data is thinned to

match the number of computing points, then FFT is performed.

Selecting the Time Window: Window

Select from the following windows.

Rect (Rectangular): Best suited for transient signals that attenuate completely within the

time window.

Hanning (Hanning): Best suited for continuous and non-periodic signals.

Flattop (Flat Top): Best suited for improve the accuracy of the level even if the

frequency resolution is to be compromised.

Power Spectrum Calculation Range

You can select the power spectrum calculation range from the following choices.

Main: Calculate using the range displayed on the main screen

Zoom1: Calculate using the range displayed on the Zoom1 screen

Zoom2: Calculate using the range displayed on the Zoom2 screen

Note

• If you perform the calculation with the range set to Zoom1 or Zoom2, when zooming the

calculation results you must use a zoom screen with no calculation range selected.

• You can zoom the calculation results so that up to 500 data are displayed.

Notes when Displaying Power Spectrums

• Cannot be executed if the displayed record length is less than number of computation

points (Point).

9.6 Displaying the Power Spectrum