User manual
2638A 
Users Manual 
4-12 
Table 4-4. Scan Statistics 
Statistic Description 
Maximum Maximum measurement. 
Minimum Minimum measurement. 
Average  Average of all the measurements taken. 
Standard Deviation 
A measure of the distribution of a set of data from its mean. The more spread 
apart the data, the higher the deviation. 
Peak-to-Peak  Difference between the Maximum and the Minimum. 
Rate of Change  A measure of how much the readings change over time. 
To view the scan data: 
1.  Start a scan. See “Start a Scan” on page 4-10. 
2.  Push  to open the Scan Data menu. After the menu opens, push  to cycle the menu 
pages to view more channels. 
3.  To view channel statistics, push . 
Graph the Measurements 
The Scan function has a graph feature that lets the user display the measurement data in a 
graph. This feature is located in the Scan menu (push 
 then push ).The graph 
automatically scales to fit all the information on the display when opened. To refine the 
data, the graph can be manipulated with the front-panel arrow keys as shown in 
Figure 4-5. 
Notes 
The maximum number of channels that can be graphed at once is four. 
Selection of two or more channels with different input types (such as 
temperature and milliamps) can make the graph difficult to read because 
they do not share the same unit. To prevent this, only select channels of the 
same input type or view the channels one at a time. 
Selected
Channels
and Key
Time Stamps
Select or Deselect
Additional Setup Options
Graph Controls
(Front-Panel Keys)
Zoom Out
Zoom In
Move Right (in History Mode)
Move Left (in History Mode)
hcn056.eps 
Figure 4-5. Graph Feature 










