Gas analyser teardown
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- Опубликовано: 21 окт 2024
- Inside the world of electro-opto-chemical things. UV sources, photomultipliers and lots of plumbing!
Check my ebay listings for parts from these :www.ebay.co.uk/...
Manual for later 43B version of SO2 Analyzer : pas.ce.wsu.edu/...
Hamamatsu R669 Photomultiplier : www.hamamatsu.c...
Datasheet for R268 photomultiplier equivalent www.hobbielektr...
I love the bit where you fix something that you don't then know how to use. Great video. Thanks.
That old Thermo gave me flashbacks to the early days in my career. We used to use a lot of the Thermo A and B series units in our network.
Until recently, I used to calibrate a 43A (photometric ozone monitor from the same instrument generation) for another agency to use as a bench standard.
I recognize the insides of the last machine, took one apart a couple of weeks ago as they emptied a university gas lab here in Oulu, Finland. It was probably a materials lab rather than environmental. Took the sensor with its amplifier board, and the "T1" transformer. Different size but identically marked "T1" transformers were used in other analyzers as well.
9:10 That is a PermaPure moisture management device of some sort. It uses Nafion (perfluorosulfonic acid polymer, kinda like Teflon with sulfuric acid added, adsorbs water but stays solid) in a tubular form to effect transfer of humidity from one stream to another (drier) one. Probably used for sample prep or oxygen conditioning prior to ozone synthesis.
Don't recall but something like £50 for all 4, plus some free stuff they were going to throw away.
do you have an ebay site with only your stuff ?
It's on the list of things to try
thanks, I'm excited to see what you are going to do with the photomultipliers.
Great stuff Mikes stuff. Excellent video!
I used to design and build the sample routing streams that feed the test substance into the analyzers. Everything thing in that industry is extremely expensive and, very much so hand made. One nox cart new would go for just under $750k, it really is a awesomely unique field. The streams would have to be heated and kept to .5 degree F over 50 feet of hose to prevent the sample trace from sticking. your literally measuring atoms in some instances. These are very common in production SAE dynos
Gain is how many electrons are emitted at the signal output for each electron emitted from the first anode.
I totally dig your videos, Mike. Fascinating stuff.
is it just me or is anything rack mount expensive?
Why are these devices so immaculately clean? I've never seen decades old equipment, especially things with fans inside, that were so spotless. Were they used in cleanrooms or something?
Vacuum pump needs to be stripped, lapped down to 5 thou end clearance and the checked again. It should do more than 30 inches into zero flow. Nice little pump there, probably made by GAST.
Thanks Mike. You made a crappy Monday bearable!
The inner tubing is "Nafion" (developed out of Umass, but I think Perkins Elmer licensed it or funded the research because I remember seeing the gear in a consumables catalog under their name, no surprise there), the outer is probably PTFE. ruclips.net/video/-arILnvePC4/видео.html . The paper was a good read, from what I remember. Google "flow injection" "university of massachusetts amherst" "moisture removal" and you'll find it
Filters on the fans, and use in a clean lab environment.
If i knew 0000000.1% of what you know .I would still be super brainy .love all your vids and im going to start commenting more ,I dont like to comment if I have nothing to contribute ,but you are one extremely clever guy
Do a teardown video about the Toshiba cat scanner machine
I had oxygen sensors where you had to buy a new sensor head every 6 months maximum ( and they only had a shelf life of a year anyway) and the sensor heads were $200 each. Tossed it and got a much cheaper one with cheaper sensors, it was used to check a inert atmosphere packing line.
For trace gas measurement, ppbv is not quite sensitive. Sub ppbv or low pptv is so called ultra-sensitive.
'tis always good when things come with decent manuals.
Again the good old Z80 :)
The Schematic at 6:33 calls for a 100 million ohm resistor by all I see at 8:15 is a 10 million
SO2 analyzer #1: flash tube looks like it might be a hollow cathode type, which emits light characteristic of the cathode material. UV wavelengths suggest something like mercury vapor (which wouldn't really need something fancy like a hollow cathode lamp, as a regular gas discharge type would suffice).
Interesting that the washer in front of the UV tube in #2 is all rusty-- that thing should be making quite a bit of ozone!
The flash tube is a Xenon flash lamp with two internal trigger electrodes, broad spectrum so it required the 4 angled reflective wavelength filters. The continuous wave finger lamp is a UV lamp with a narrower wavelength spread and only has the single band pass filter in front.
I have examined a newer instrument and the optical system is still almost the same, CW UV lamp, single filter, heated block, optical feedback and Peltier cooled PMT tube detecting light in the common volume, with the extra band pass filter to block the excitation light and pass the SO2 fluorescence wavelength.
It also had a concentric tube-in-tube scrubber that was there for removing hydrocarbon vapours from the sample stream and had an option for an internal span sample source, basically a vial of SO2 with a Teflon seal that diffuses a tiny amount that is calibrated at 75degC I think. The source cannot be left in these machines as it will contaminate everything if the pumping system does not continuously purge the piping to the outside.
Ozone does rust stuff.
Hollow cathode tubes are generally of a different construction with the optical output emitted from the hollow cathode area. Usually they have heat fins inside the tube too as the cathode runs hot.
Loved this teardown.
Amazing how one can dive into exotic, high tech instruments and know pretty much what section does what and that the insulating fiber is some RockWool stuff and not Asbestos. I guess asbestos is more grayish in this form.
How much did you pick these up for? I know you said very cheap but what's very cheap with something like this?
The input for the ozone generator is likely to be fed with bottled oxygen, as the nitrogen in the atmosphere would react with oxygen to form Nitrogen Oxides, which would then mess up the results...
I have to wait to watch this because of school today for something stupid and then I'm "off" again the one day I have to go in be for its all over cant. wait to watch the video looks great.
Awesome stuff keep it up!
Could you be more precise how much did you pay, please?
Greetings
Why do you get to tear down such awesome things?
by peanuts what do you mean
23:20 was interesting :) not seen one so simple yet so obvious how it works. I'm now going to start my own photomultiplier manufacturing company to shake up the market as hamamatsu has obviously been monopolizing the market too long! :p
Ah, wonderful. I'm not the only one who gets the anode and cathode confused.
So what'd would the 2013 equivalent of these massive sensors and assorted electronics be? :)
Even today 2022 they are surprisingly similar. More computerisation and automated calibration, the sensor in a newer unit I investigated is functionally identical to the second unit Mike disassembled. Look up Teledyne API NOx and SO2 fluorescence analysers, you can find pictures of the internals on the web and they are the same as these old units.
or a MRI scanner please
Some PMTs can detect a single photon.
where do you get this stuff from ?
Mark Hodgson He says it at the beginning of almost every video: eBay.
How the hell do you get this stuff!!!!!
"Formerly very explosio.. originally very expensive"
HA!
Rather elaborate bit of kit. Shouldn't it be possible to forego all the icky chemistry and just agitate the molecules with the right laser frequency and look for the response?
consumables approach is ugly.
and why not be able to detect a multitude of molecules instead of just one.
Dan Frederiksen bit late but search for "FTIR"; that detects multiple substances at one go...
I'm french, if you need some translations ;)
Popcorn time! :D