PID Noise

Chromatography Forum: GC Archives: PID Noise
Top of pagePrevious messageNext messageBottom of pageLink to this message  By craig on Monday, April 23, 2001 - 11:52 am:

I have an OI 4450 PID/FID combination. The PID is suffering from a lot of random noise, +/- 0.5 mV. I have tried changing lamps, cabling, the power supply and the electrometer board. All with no luck. I don't think the gases are a problem, because I am running the same setup off the same cylinders.
Any suggestions?


Top of pagePrevious messageNext messageBottom of pageLink to this message  By Anonymous on Monday, April 23, 2001 - 12:22 pm:

You probably have a leak in the PID if you have a lot of noise and have swapped out all the components above. There is a Vespel ferrule in the system where the makeup adapter enters the base of the PID which tends to shrink a little over time, especially if the detector temperature is cycled on and off. There is also an O-ring under the lamp which must be changed periodically. Another possiblity is a contaminated column if you are running samples with diesel range organics in them.

Hope the above helps. Don't forget that OI has a toll-free technical support line so you can talk to one of their people for troubleshooting help.`


Top of pagePrevious messageNext messageBottom of pageLink to this message  By Anonymous on Wednesday, April 25, 2001 - 02:15 pm:

I have had problems with leaks/and dirt in the makeup adapter apparatus. It was the source of my PID noise problems.


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