Hi. I need your help. What is the Full Width at Half Maximum (FWHM) of this function ( look at the picture) ? http://imageshack.us/photo/my-images/835/immaginezxa.png The operating voltage of a PMT is in the order of 1710V. I've to find the PMT gain. The peak value is near channel 630. The pedestal peak is near channel 66. Could you help me, please? Thanks anyway.