I want to use the dual inlet for reference gas injection when using the gasbench and also the TC/EA on a MAT 253. I have been able to set up the configurator for a gasbench+dual inlet and have added the "reference" scripts for opening and closing the dual inlet changeover valves. This works great. However, the beam intensity of the reference gases drops quite a bit after 12 hours. I would like to be able to have the beam intensity from the dual inlet remain constant over 12 hours or more. For this I need to get Isodat to adjust the bellows pressure before each run and I am clueless as to how to set this up. Is there anybody out there who is using the dual inlet for reference gas injection and has figured out how get the instrument to maintain a constant pressure in the bellows throughout the day? I know you're out there! Thanks for any help! Anthony ------------------------------------------------------ Anthony L. Michaud Physical Sciences F-686 Arizona State University Tempe, AZ 85287-1404 Tel: 480-727-8033 Fax: 480-965-8102 ***Windsurf Everywhere*** ------------------------------------------------------