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- Posts: 2
- Joined: Sat Jun 14, 2014 10:47 pm
I purchased a barely used DX-120 in 2009 it was in perfect shape except there was a restriction in the plastic tubing leaving the cond detector causing high back pressure. I knew this from the get go but was able to clear it enough to run until recently, burned through 3 new suppressors in 4 months this year due to high pressure...all because of this restriction. Mind you this tubing is welded into the metal plate of the detector, this tubing is plain ol clear plastic tubing same as the tubing for the autosampler sampling tip.
WHY? why weld a simple plastic tubing to the metal plate of the detector? Perhaps to save space so the insulating cover fits, but I don't think so, there is no reason to do this they could have left an unwelded hole this tubing fits through so that it can be replaced if plugged!
So heres what I did, instead of spending north of 2K for a new detector, it dawned on me....bypass it! I took an old sampler tip line of same tubing as the welded tubing, cut it to length and installed, reassembled the detector with the new bypass (was just like doing bypass surgery, yet on a machine haha).
It worked, it worked so good that its like a new IC, pressure is at 1400 psi (vs 2000+ and leaking SRS) perfect chromatography and a shorter run time for the typical anion run, yet to do the cation run but should be drastically improved (vs no peaks in cation run) - will let ya all know tomorrow, got 100+ samples to bang through tonight.
The point is that this is bad engineering by Dionex (or whoever made this detector) all plastic tubing on an IC is prone to blockage and should be able to replace, sure looks like someone at corporate said...hay lets make this fail eventually so they gotta buy a new pricey detector from us!
WHY? why weld a simple plastic tubing to the metal plate of the detector? Perhaps to save space so the insulating cover fits, but I don't think so, there is no reason to do this they could have left an unwelded hole this tubing fits through so that it can be replaced if plugged!
So heres what I did, instead of spending north of 2K for a new detector, it dawned on me....bypass it! I took an old sampler tip line of same tubing as the welded tubing, cut it to length and installed, reassembled the detector with the new bypass (was just like doing bypass surgery, yet on a machine haha).
It worked, it worked so good that its like a new IC, pressure is at 1400 psi (vs 2000+ and leaking SRS) perfect chromatography and a shorter run time for the typical anion run, yet to do the cation run but should be drastically improved (vs no peaks in cation run) - will let ya all know tomorrow, got 100+ samples to bang through tonight.
The point is that this is bad engineering by Dionex (or whoever made this detector) all plastic tubing on an IC is prone to blockage and should be able to replace, sure looks like someone at corporate said...hay lets make this fail eventually so they gotta buy a new pricey detector from us!
