FID detector noise

[fpcwsr]

How much baseline noise should I be getting with an FID on an SRI 8610B GC? I've been getting some peaks greater than 5 mV then a steady rise to almost 90mv as it continues running just straight helium. I just took over the lab ad the equipment so I don't quite no the ins and outs yet.

Thanks

[chromatographer1]

This is too much noise.

One of your gases may be contaminated.

Or someone put something into the injector they should not have.

Do you see a flame in your FID? You shouldn't.

best wishes,

Rod

[AICMM]

fpcwsr,

A dirty jet might cause this although there is not much of a jet in the SRI. A bad electrical connector to the amplifier could also cause this, especially if the collector wire runs over some other electrical source. You might also try turning your ignitor voltage to off if this is one of the units that continuously runs the ignitor.

Best regards,

AICMM