Search found 265 matches

by David Kunkle
Fri Aug 11, 2017 1:58 am
Forum: Vacuum Technology (& FAQs)
Topic: TMP Diagnosis
Replies: 31
Views: 17537

Re: TMP Diagnosis

Never heard of a Rigaku turbo. I looked at their site out of curiosity, and they obviously no longer make or sell turbos except as part of an instrumentation package. Maybe they used to sell turbos with their name on them long ago, but the manufacture was farmed out to Varian? You said it was "soake...
by David Kunkle
Wed Aug 09, 2017 2:03 am
Forum: Vacuum Technology (& FAQs)
Topic: TMP Diagnosis
Replies: 31
Views: 17537

Re: TMP Diagnosis

I see a TC in the first pic, but you make no mention of what pressure the roughing pump achieves? You mention 75 microns like it's the factory rating. A worn pump or a small leak would easily put the pressure outside the range where a turbo can operate. I'm still trying to fathom how you spent $50 i...
by David Kunkle
Tue Aug 08, 2017 3:38 pm
Forum: Vacuum Technology (& FAQs)
Topic: Bad Ion Gauge Tube?
Replies: 10
Views: 3094

Re: Bad Ion Gauge Tube?

It had been a few years since I put my gauge system together. Meaning I forgot the tube and cable types have to be compatible. I realize now my cable is for a single filament. The tube had 1 broken filament, and I recently realized it was contaminated with a thin film of something that wouldn't wash...
by David Kunkle
Sun Aug 06, 2017 12:26 am
Forum: Vacuum Technology (& FAQs)
Topic: Bad Ion Gauge Tube?
Replies: 10
Views: 3094

Re: Bad Ion Gauge Tube?

If the Varian is switched to filament #2, it does nothing no matter how everything's connected. The jumper is already set to 563- same as the last tube required.
by David Kunkle
Sat Aug 05, 2017 1:47 am
Forum: Vacuum Technology (& FAQs)
Topic: Bad Ion Gauge Tube?
Replies: 10
Views: 3094

Re: Bad Ion Gauge Tube?

No fight there at least. Probably went bad when a real scientist was using it, and he threw it in a corner to collect dust (in case he might need it someday). Winds up in a box many years later that gets auctioned off for pennies. Someone like me without a $1M government grant buys it off ebay. Heav...
by David Kunkle
Fri Aug 04, 2017 10:55 pm
Forum: Vacuum Technology (& FAQs)
Topic: Bad Ion Gauge Tube?
Replies: 10
Views: 3094

Re: Bad Ion Gauge Tube?

Since you mentioned that, I took a close look inside with a flashlight (kinda hard since it's a coated tube). There is another filament on the opposite side from the one that momentarily glows. That filament is broken near the middle- not touching anything far as I can tell- but broken. It's what I ...
by David Kunkle
Fri Aug 04, 2017 10:06 pm
Forum: Vacuum Technology (& FAQs)
Topic: Bad Ion Gauge Tube?
Replies: 10
Views: 3094

Re: Bad Ion Gauge Tube?

My Varian will shut down the tube at 100 microns. Everything worked fine with that first tube I had. My TC tells me I'm down to 5 to 10 microns. No problems until I switched to this new tube.
by David Kunkle
Fri Aug 04, 2017 6:39 pm
Forum: Vacuum Technology (& FAQs)
Topic: Bad Ion Gauge Tube?
Replies: 10
Views: 3094

Bad Ion Gauge Tube?

Had a problem with my first ion gauge tube, so I got this used tube off ebay: http://www.ebay.com/itm/ETI-Electron-Technology-8142-TK-Glass-Bayard-Alpert-Ion-Gauge-Tube-8142TK-/112005979628?_trksid=p2047675.l2557&ssPageName=STRK%3AMEBIDX%3AIT&nma=true&si=4h7eccNwtD4NsNk4jSMWBKw3U0s%253D&orig_cvip=tr...
by David Kunkle
Mon Jun 05, 2017 10:17 pm
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: New neutron detector available
Replies: 20
Views: 9255

Re: New neutron detector available

Very nice. Looks like you made the entire thing with a 3d printer?
by David Kunkle
Wed May 24, 2017 3:57 am
Forum: Vacuum Technology (& FAQs)
Topic: Chinese pump first run report.
Replies: 11
Views: 9178

Re: Chinese pump first run report.

My Trivac D4A in excellent condition can get to about 5 microns. You stated your Chinese pump gets down to 1-2 microns. I not sure any 2 stage pump can get that low- never mind a cheap Chinese pump. The accuracy of your TC gauge may be questionable. The 37 millitorr stated on the label seems more li...