From: Philo, John <jphilo@amgen.com>
  To  : 'rasmb@bbri.harvard.edu' <rasmb@bbri.harvard.edu>
  Date: Mon, 9 Dec 1996 14:01:45 -0800

RE: spikes in xla data.

Those spikes occur when the flashlamp fails to fire, and may be either
positive or negative depending on whether the failure happens when it is
reading the sample or reference sectors.  This occurs intermittently in
all XL-A/I's, as far as I know. If you are averaging many data points at
each radius (for example in an equilibrium run), the spikes tend to
average away too so they are not quite so obvious as they are in
velocity runs, where typically one is not averaging but taking lots and
lots of data.

John Philo
>----------
>From: 	pascal[SMTP:pascal@bcserv.wustl.edu]
>Sent: 	December 09, 1996 1:38 PM
>To: 	rasmb@bbri.harvard.edu
>Cc: 	pascal@biochem.wustl.edu
>Subject: 	spikes in xla data.
>
>hey all!
>
>Does anyone else see occasionaly random spikes in the their sedV scans 
>on the xla?  This is nothing systematic, they just appear from time to 
>time...   I put this down to just random noise or an instrumental 
>glitch, but Tim (Lohman) wanted me to check just to make sure..
>
>Thanks.
>razmic
>