X-ray fluorescence spectrometer teardown - Scitec MAP Spectrum Analyzer

[@MrBrycart]

I built over 600 of these back in the day. Except for the PS all the boards are rather narrow. they were designed to also fit a probe that could also be lowered into a bore hole for mining or clean up sites. That console still has the residual software to accommodate the winch and count off the depth in feet. The two analog switches are part of the sample hold circuitry and that entire board was used to take a few micro second pulse and stretch it out to I think 100 ms or more so the hybrid chip could count it. The source holder (we called it a tumbler), was made of tungsten and the source was held in with a set screw and dab of silicone glue. The plunger in the front was designed in for customers on the east coast because they wanted more protection - wasn't necessary. Typically mining and environmental cleanup people didn't use them. The two transformers on the other long board combined the signal to and from the +/- 18V power. Each unit has a unique calibration. The detector was silicone was purchased from Micron in England. All the gaskets, black bumper and detector holder were pour by me...made me itch after awhile.

[@tesla500]

Great to hear from someone who actually built these, thanks for the story and info! Any idea what they sold for back in the day? How long did they remain in production?

[@MrBrycart]

The LBP systems I believe sold for $18-$25,000. They were kind of cookie cutter since they were calibrated to standard paint thicknesses and substrates (concrete, sheetrock, plywood, etc.) Mining and waste sites were more costly because calibrations not only needed a represented detection element but also an example of their soil/rock matrix. One company with two different Molly/Tin mines could not swap instruments because each instrument was calibrated to a given rock matrix or location.

[@MaxKoschuh]

awesome comment. thanks for all the additional information !

[@AppliedScience]

Cool teardown!

[@mikeselectricstuff]

I wonder if maybe the sensor is some sort of ionisation gauge, or maybe an avalanche photodiode

[@brainndamage]

mikeselectricstuff Or some scintillating material coupled to the photodiode, like a miniature version of the photomultiplier based probes.

[@Nitrxgen]

I knew I'd see you here, Mike :D

[@ciprianpopa1503]

Lead detection is done in this case beyond 70 KeV, based mostly on its kalpha at ~75KeV. Most likely the detector is a CdTe or a CdZnTe semiconductor.

[@Spirit532]

Modern handheld XRF devices, even those smaller than this one, use actual x-ray tubes! They're absolutely tiny, no more than your thumb's width and length, and are usually rated at an incredible 50-70kV(keV photopeak) output! Obviously at a few microamps, but still. You'd likely require a license to own this if it had a gamma source still in it, and taking it apart would be illegal in most countries(including Canada), without another license. The window on the photodiode is indeed beryllium, as is the one on the front, because you're dealing with soft, low-energy and low-count x-rays, and the insides can only really be one of two options: a bare photon-counting APD or a PIN photodiode with an extremely thin coating of scintillator, probably CsI:Tl.

[@berni8k]

That hybrid chip is most likely a successive approximation ADC and most likely some sample and hold circuitry in front of it to capture the magnitude of the short pulses from the photo diode.

[@NickMoore]

Very cool. I like the double shutter on the x-ray source, even the gamma sources I work with only have a single shutter but they are spring-loaded to fail safe.

[@trustthewater]

I got to help an engineer get a Thermo Niton XRF working with a laptop a few years ago. Those things are absolutely amazing and I've been trying to get my hands on one ever since then. Problem is, you need some serious money for working units. Does this mean you going to do a kickstarter for a cheap XRF unit? Please do. I can't even begin to imagine the legal issues of producing an x-ray device even if it doesn't use a gamma source but you would be a true hero. More so.

[@pirateman1966]

That hybrid looked amazing. Thanks for sharing.

[@slowbrohime]

I'm always so happy to see a new post from you. Cool teardown!!

[@johnpossum556]

Send the de-sardined chip to electronupdate, he has a microscope and weekly gives us interesting decapping vids so he is used to looking at that stuff. in fact until the apology I thought I was watching another one of his vids.

[@DextersTechLab]

Interesting teardown! Shame there was no source in there but sounds like the half life wasn't that long on them anyway so probably not a great loss. Could the detector be an APD which would need a HV supply? (i am kind of mirroring Sparky Projects's comments about the inductors and 555). Oh, nice Ludlum BTW, which model is it?

[@tesla500]

I should try powering it up and measuring the diode supply. The Geiger isn't mine unfortunately, I borrowed it from Jax at The Hackery, a local electronics recycler.

[@Peter_S_]

One the CPU PCB, the PLCC chip in the lower left without the label is the CPU, a Hitachi HD64180 which is a souped up Z80 and the PLCC with the label appears to possibly be an Altera FPGA.

[@sparkyprojects]

If you're going to use the sensor, keep hold of the amplifier, it may be useful to interface your project. Not sure, but it looks like that coax to the power supply goes to the transistor and driven by the 555, could the components on the amplifier board be inductors ? the 555 may be providing switching supply boosted by inductors to give a higher voltage, hopefully you already know how geiger counters work.

[@todkapuz]

also a pancake detector is not really ideal for the radionuclides of interest here.... i mean if its a HIGH HIGH activity source, it will... but most pancakes are poor at low energy gamma/x-rays. but better than nothing. But yeah, I love the tube-vased xrf.. much better fidelity in identification.. butyeah... even with the compact tubes... no where near as small as some of the nuclide-source ones... but yeah... the nuclide ones are regulated in just about every major locations... so would be had to get hands on one except major disaster without a license.

[@loberd09]

I've got access to a high quality 2500x scope and a SEM. I couldn't reverse engineer the mystery hybrid module but I could get the images for those who could.

[@robmckennie4203]

assay is like, a kind of analysis. you "assay" a sample to find out what's in it. that's why the unit menu said unit for assay, and I expect the assay option below the 2 button in that main menu is how you'd take a measurement

[@krishna34674]

The LM3080 on the amplifier pcb is actually an operational transconductance amplifier ... odd seeing that there..

[@MegaGamerGuy1701]

if im not mistaken that metal/ceramic IC is a beta battery

[@Migueldeservantes]

I want that super capacitor! That is the piece of resistance man!!!!

[@jaeweld19]

I believe that shutter that goes down in front of the source would be made out of tungsten.

[@MrBrycart]

Yep, also tungsten.

[@ciaranfarley]

wait you can use the chronos as a normal camera? i guess you would call it a mirorless form factor

[@Firecul]

Good news is it would handle the 60fps no problem at all :)

[@TheBobby416]

Thank you for your time.

[@apl175]

Was worried about no cameo, until 1:54

[@DJignyte]

I did find this interesting. Cheers, man!

[@SupremeRuleroftheWorld]

that is a nice camera, got any more info on it? /sarcasm mode off

[@Firecul]

14:34 - Well there's your bug

[@graywolf2694]

I wish there was a ewaste center by me that would let me take or buy stuff off em.

[@electristic]

Interesting, sucks you couldn't get the source though.

[@fizzyplazmuh9024]

"Source may be competely dead" Hah! A sense of humor. Notice Trixie had the sense to clear out by then? She's not taking any chances. We had a spider monkey that lived at the electronics lab I worked at. She would try to park in the middle of whater we were doing but once you mumbled "Watch out" she knew it was about to get dangerous and would scoot away.

[@jerzmacow]

Lol.. Marks geiger counter. Also, I think I gave it to you like 2 years ago...

[@tesla500]

Haha. We should run that 24kW lamp fixture sometime

[@jerzmacow]

media.giphy.com/media/L4caiF7GTkgJa/200.gif

[@addman]

and... a cat

[@Atom-scan]

лайк

[@dgretlein]

Sorry, no cats. Gotta go.

[@geniotorres2520]

Do u have an Instagram account to follow u? @tesla500 ?

[@benharriman8687]

Hey, I am a 13 year old youtuber that is getting into basketball and I want to start vlogging. Can you make a cheap camera with a mic and put it on amazon please?

[@NoisyPlaces]

Y2K compliant !

[@Firecul]

I hear there was quite the popup industry for testing that stuff.