Chromatography Forum

Hi all;

I am working with a Trace Ultra GC, coupled to a Finnigan Mass Spec. Yesterday, my boss and I changed the fillament in the ion source. Everything pumped down fine, but now the source refuses to heat up ( the read back is 22 C, Set point 200). The transfer line is at 250 C, so I suspect the issue is with the thermocouple, and not the heating element. The ion source itself is a combined EI/CI source, operating in EI mode.
Under these conditions, is there any risk of damage if I turn the fillament on ? I'd like to at least see if it is operating properly.

may be u did't fix wires properly

Thats a good suggestion.

I took the source out this morning, all of the wires were connected. However, one of the leads for the thermocouple was in electrical contact with the adjacent guide post. I corrected this and re-installed the source.

she's pumping down now, so we'll see what happens.

By the way, I found out it is safe to turn on the ion source. The heater is there primarily to keep larger analytes volitile ( thus preventing buildup). Its ok to look at the H2/N2/O2/H2O ions for a leak check. It would be unwise to inject something like methyl stearate (one of our standards).