Chromatography Forum

I have a 5971 MSD. The MS temperature read out under "Vacuum status" is 369. The MS interface/transfer (DET B) is off.

I think it's a board problem with such a high reading. It doesn't change if you turn Detector B off or on or anything.

The setting when normally run is 310 C. The temp. on the interface usually reads 190 aproximately.

Thank you for any information.

It may just be the temperature sensor and not a board. I would try replacing the sensor first, then replace the board if that doesn't work.

BCBC,

The MS transfer line gets it's temperature from the GC so if it is a board problem, it would be the motherboard of the GC not anything to do with the MS. So I am a bit confused. You are seeing the error in the MS software (under the tune and vacuum control) or you are seeing the error on the GC side?

Best regards.

The error is in the software under "Vacuum Status".

When the transfer line heater is cooled to room temp the GC temp reads about the same, ambient.

If the setpoint of detector B (Interface heater) is set to 310 C eventually the actual temperature will read 310 C on the GC display.

Going to the "Vacuum Status" will show about 370 C.

Also this will print on a tune as the MS temp.

I just thought of something. I did change the ion source right before having the problem.
I think maybe the RTD on the source/quad housing may not be making good contact.
That would account for the GC being happy with setpoint and actual temperature. No problem there since that is working normally.

The wrong temperature read out is coming from the MS.

That's it. Screw was loose holding the RTD.

Thanks for the ideas.