Scan Length

 

The first step in removing errors is to check and see if the various scans are of the same length.  To view a list that can help make such a comparison, click on "File Info Table" in the LX Panel.

 

Place Pointer over the marked region to zoom inMove Pointer Away To RestorePlace Pointer over the marked region to zoom in

Place Pointer over the marked region to zoom in

 

 

 

The File Info Table pops up.

 

 

The "scan_read" column shows the number of data points found in each of the datafiles.  In this example, it can be seen that the fifth scan is not the same length as the rest. When files of different lengths are included in the averaging, the energy range is truncated to that used in the shortest scan.  In order to average the full length of scans 1 - 4, scan 5 must be excluded from the averaging. To do this, set the "scan_wt" of that particular scan to 0 from 1.

 

Important detail: In order to change values in IGOR tables such as the File Info Table, you must

    1. Click on the value you wish to change (in this case, the last entry in the scan_wt column)
    2. Type in the new value (0)
    3. Either hit "Enter" or click on another box within the same table.
      Step 3 is the important detail that is easy to forget. In this example, if after step 2 you click next on the "Plot T" button of the LX panel, the new value of scan_wt(file 5)=0 will not be remembered by IGOR, even though it will continue to show in the selected cell of the File Info Table.