Chromatography Forum

I need help, can you help me to know which is this detector in the GC 3400 of varian?

The silver tower with the coaxial cable attached looks like a PID to me, not sure if is it a tandem with FID or ELCD with the larger block it is mounted on or not.

Agreed with James on the likely detector identity. The pneumatic controls on the front panel should positively ID it, though. I think I've only had one 3400 pass through my hands that even had a detector in it, and that was an ECD(all the others were set up to work with things like the Finnigan Incos or TSQ.

With that said, I'd be leery of going down the path of a 3400. It's a bit newer of a design than the HP 5890, but Varian GCs never sold in the same quantities as HPs and there are fewer folks who know them now. Also, if you want to run it with a computer(as opposed to a strip chart/integrator), you need the LAN card which can be a bear to find it not present(unlike the HPIB card for the 5890). There again, I've never been too deep in Varian GCs outside them being MS front ends, but I don't remember them even having a good "external control loop" system like the HPs(where you could tie the GC, integrator, and autosampler together and program them using INET or HPIL), even though I'd not be too inclined to run anything short of a computer these days. There are options for simple data handling these days through an A/D converter(some folks even use a sound card) but of course you lose full instrument integration.

Thank you all for giving me your opinion, they are very well received, the fact is that if it were a PID I would need a power source for the UV lamp, and I do not see it in the equipment, this is equipment that is for sale on ebay and I don't want to buy it if I'm not sure about your detector and the seller doesn't know what kind of detector it is

It looks like the black coax is connected from the PID lamp to the large (aluminum) piece on the circuit board so maybe the power supply is built into the system for Varian.

We had one on a HP5890 and it has a small box beside it to power the lamp, it was an OI detector that was also in tandem with an ELCD, which had a reservoir for the alcohol and a pump for it to the reactor. They were good detectors but requires constant maintenance to keep them going well.