Time Scaling

Time Scaling

The Time Scaling is very flexible, and can scale from viewing over 24 hours to less than 1 second in a window.

There are a number of ways to adjust the time scaling:

  1. Use the buttons on the toolbar of the WaveView window. The button increases the scale (zoom in, or expand the waveforms), and the button decreases the scale (zoom out, or squash the waveforms).
  2. Use the Left and Right arrow keys on the keyboard. The left arrow key increases the scale, and the right arrow key decreases the scale.
  3. A mouse wheel can be used if fitted and drivers installed. Hold down the Shift key whilst turning the mouse-wheel. Turning the wheel up increases the scale, turning the wheel down decreases the scale.

The time line at the top of the window adjusts its display depending on the scaling factor in use. The tick marks grow larger, representing bigger time steps. Note that the smallest unit of time mark is one second. To measure steps smaller than this, use the measurement cursors.

The time scaling is displayed in units of pixels per second. i.e. for a 100sps data stream at scale 20, each pixel represents 5 samples. At a scale of 100 the scale is 1 pixel per sample.

When small scale values (only a few seconds displayed) are used in conjunction with large windows, the time required to scroll the window can exceed the number of seconds scrolled. In this case, the display can fall behind on real time. If this situation is detected, the scrolling will not occur in order to maintain real time display. This will result in a ‘jumpy’ display. To recover, the time scale should be increased.

Although the time scale can be set to view very large time intervals (over 24 hours is possible), any screen re-draw can only display the data in the stream buffer. (see Stream Buffer). If left undisturbed, the waveform display will fill the entire window. Note also that the page print facility uses the stream buffer also. To capture the window display use the Windows facility (ALT-PrintScreen to copy the window to the clipboard. The bitmap can then be pasted to a word processor document, graphics package or printed).

See Also :

The WaveView Window, Measurement cursors, Amplitude Scaling, Print Features