Last Revised: 09/19/06 By: KLL
Keywords: timescale, proportional, control chart, MF, horizontal scaling
DataLyzer® Spectrum software platforms with the B4 registration code have a proportional graph scaling feature available. This feature allows users to view graphs based on a timescale with proportional space between points based on time rather than using an evenly spaced subgroup scale. This allows a view of runs and trends in the data on an hourly basis which is truer to real life.
Implementation
Timescale graphs can be implemented globally, or by characteristic.
To implement timescales globally, select Setup/Preferences/Define Preferences.
To implement timescales by characteristic, open the characteristic, and select Preferences/Set Preferences.
Select the “Control Chart Presentation” tab. The horizontal scaling area is located in the lower right-hand area of the control chart presentation tab. Enter the number of hours you wish to display on the control chart graph and press “save” and “exit”. The maximum display is 48 hours. To revert to default spacing where the past 25 subgroups are spaced evenly regardless of time, press the “25 subgroups” button.
The following graph is an example of a timescaled graph. Notice that some data points are spaced further than other data points. This is because the further spaced data points had more time between sampling. In areas where data points are closely grouped horizontally, many data readings were taken in a short amount of time.
The graph below is an exact replica of the graph above, except the data was plotted in the default manner with uniform subgroup spacing regardless of timing of entry.
DataLyzer® Spectrum Application Note
Compliments of DataLyzer International, Inc.