PID

[KMULROY]

I'm looking for information regarding dropping PID responses. Is anyone having this problem? We are running CS2 the majority of the time.

Please respond via message board or via email.

Thanks

[chromatographer1]

The two most common reasons for loss of PID signal is a failing light source or a dirty window from column bleed or some other contamination.

[KMULROY]

We have tried the lamp. Unfortumately this is not the problem. We have also tried installing a new column in hopes of fixing the problem. Moisture at one point was suggested so we have also attempted drying our CS2 with various agents.

Our gases do not appear to be the problem as other instruments supplied are not affected.

I am running out of ideas. If anyone can help please reply.

[JI2002]

You need to isolate the problem, it could be detector, column or injector. If you use purge & trap as sample introduction, it could be P&T. Aslo try to figure out what had changed before PID response dropped, did it drop gradually or suddenly when you ran a nasty sample?