Search found 731 matches

by Jerry Biehler
Fri Jul 05, 2019 6:00 am
Forum: Images du Jour
Topic: Nuclear-powered quadcopter going to Titan
Replies: 4
Views: 3715

Re: Nuclear-powered quadcopter going to Titan

You could do a permanent magnet bearing since the load is pretty much only axial. That means just one point of contact at the end of the shaft and you could probably do something like MolyDiSulf or CBN thrust bearing.
by Jerry Biehler
Wed Mar 27, 2019 5:55 am
Forum: Vacuum Technology (& FAQs)
Topic: making a connection without admitting gas
Replies: 5
Views: 5091

Re: making a connection without admitting gas

The taps that refrigeration guys are way better than what you can get at a hardware store. Get some of those. They can handle pretty high pressures, pressures in refrig systems can get pretty high, higher than your 60psi.
by Jerry Biehler
Thu Mar 14, 2019 1:01 am
Forum: Vacuum Technology (& FAQs)
Topic: Micro-Ion ATM gauges on eBay
Replies: 10
Views: 8432

Re: Micro-Ion ATM gauges on eBay

Chris, those are DeviceNet. Good luck talking to them.
by Jerry Biehler
Mon Feb 18, 2019 6:00 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: A semi-DIY preamplifier for radiation detectors
Replies: 28
Views: 14613

Re: A semi-DIY preamplifier for radiation detectors

You could use a cheapish isolated DC/DC converter module. They have basically no ripple. You definitely wont see any 60hz!
by Jerry Biehler
Mon Feb 11, 2019 5:12 am
Forum: Vacuum Technology (& FAQs)
Topic: Poor performance of old diff pump.
Replies: 13
Views: 9647

Re: Poor performance of old diff pump.

The gauge heads ought to be able to be cleaned to get them working again. I would probably start by washing them out with mineral spirits to dissolve the oil and then acetone. I would be surprised if the filament on the ion gauge ever even turned on at the pressure you were getting.
by Jerry Biehler
Wed Jan 16, 2019 7:52 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Integrated Lab Measuring and Controlling (Labview, Labjack, ...)
Replies: 38
Views: 17011

Re: Integrated Lab Measuring and Controlling (Labview, Labjack, ...)

No, I didn't hack the sensors, they come with analog out as standard, in the manual they tell you how to decode the voltage signal to get useful information. I just apply the math in labview and I get my pressure reading out. I have a 2465 too, good scope. If it is the original 2465 they have an iss...
by Jerry Biehler
Sat Jan 12, 2019 2:05 am
Forum: FAQs: Vacuum Technology
Topic: FAQ - Never turn on a turbo or diff pump until....!!!
Replies: 2
Views: 5501

Re: FAQ - Never turn on a turbo or diff pump until....!!!

If you are direct pumping to a chamber with a turbo you can start the roughing pump and turbo at the same time with newer turbos. Even says so in the manual, they are power limited and will not come up to anywhere close to speed until they have a good enough vacuum to run. I would still pump down a ...
by Jerry Biehler
Fri Jan 11, 2019 9:06 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Integrated Lab Measuring and Controlling (Labview, Labjack, ...)
Replies: 38
Views: 17011

Re: Integrated Lab Measuring and Controlling (Labview, Labjack, ...)

I used labview to control my vacuum system that I have been building for ebeam deposition. I needed to talk to things like my VAT valve which is controlled through RS-232 so it was really the simplest way. I used something similar to a labjack to handle the analog outputs from the pressure sensors I...
by Jerry Biehler
Tue Jan 01, 2019 11:23 am
Forum: Vacuum Technology (& FAQs)
Topic: The Importance of TC Gauge Calibration
Replies: 13
Views: 9069

Re: The Importance of TC Gauge Calibration

The 531 is a full range tube, 1 mtorr to atm, can't tell what the other tube is but it may have a shorter range which will give better accuracy at the lower end. But are you sure the televac controller and the tube you have matches?
by Jerry Biehler
Mon Dec 17, 2018 8:49 am
Forum: Images du Jour
Topic: Mass Flow Controller
Replies: 5
Views: 2440

Re: Mass Flow Controller

You can actually change the fittings on most MFCs. The swagelok or vcr fitting unscrews to a 9/16" o-ring seal fitting which is a pretty standard block fitting for swagelok.

I was going to say 10cc was going to be pretty big when I read it. 5cc is about the smallest I normally see.