[Aavso-photometry] Question concerning linearity of CCD chip

[actuary at mchsi.com]

To All:

I am reading "Lightcurve Photometry and Analysis" by Brian D. Warner.  On page 
91, a procedure for testing the response linearity of a CCD chip is 
described.  I am confused as to the meaning of the sentence "Find the average 
of the maximum ADU values for each star at a given exposure...".  Say 5 
imagess at 1, 2, 4, 8, and 16 second exposuress are taken. For a specific star 
there are 5 images at 1 a second exposure.  Takling the maximum ADU for the 5 
images for the specific star provides a singlr value.  However, the procedure 
says to find the average of the maximum ADU values ... The average of the 
single value is the same value. Since the test involves plotting the values 
obtained through the application of the "averaging.. maxumum" algorithm by 
exposure time, one does not average over exposure time nor over all stars.  
Clearly I am misinterpreting the description of the procedure.

I would appreciate some guidance as to the correct interpretation of the 
procedure.

Thanks

Larry