Yep same thing happens to me, I think it's the big beard but I always get "randomly" selected... I have wondered if dodgy people specifically line up behind me thinking they'll test me and leave them alone
This is an ion mas spec device. I worked for the company Smiths Detection who manufactured this version. The major selling point of Smiths Detection's Mass Spec's is their ability to detect particles at atmospheric pressure and particles can be detected continuously. The incoming air into the chamber cannot have any water. If any water did exist is was such a insignificant amount would as to not deter from analysis. I was part of a team who worked on these types of devices. I would see this version on my colleagues desk during development. I believe this version would be sold to law or border enforcement and be configured to detect drug samples. Where as, I worked on the Command and Control systems that interacted with mass specs installed in air ducts. These systems would analyze the fresh air intake for biological or chemical warfare agents. They also produced portable units for use in the field. Some footage can be found, during the Gulf war , of US troops using the portable version to detect various substances on found weapon caches..
@@gsuberland Well I was part of a project, where we hoisted a powder coated box, with a detector inside, on top of a pole. That was used in a Port Authority in a rail yard where tanker stored all kinds of bad chemicals. The system was placed there for remote monitoring of the environment around the rail yard, more emphasis on the tankers.
To be precise, it is not a mass spectrometer it is a drift tube ion mobility spectrometer, which is a related instrument type to a Mass-Spec but not the same. The water aspect is interesing: I was asking myself if the ion chemistry in the source region is primarly driven by protonated water clusters, which would probably lead to poor ionization efficiency or if the gas is dry enough to have the nitrogen species as primary ions. Do you have an estimation of the maximum tolerable background water concentration in the gas? If water broke through the inlet filters: Did the ion peaks distort or shift or did the analyte signals vanished entirely and only a large reactant ion peak remained?
I used to work for Smiths Detection. When they bought Barringer, they eventually closed the Canadian plant and moved production of the consumables (Swabs, etc) to our plant in the US. I was one of the people who helped set up the production line. I used one of these to test the consumables we were making at the time. I moved into tech support later but was never trained on the 400B since it was being phased out by then. It was replaced by the 500DT and recently the 600, which no longer used a radioactive source. Consumables are now produced in Malaysia and the equipment is built in the UK.
I have an unfortunate amount of experience with the 400B. These machines live in nightmares. They're effective, but do generate quite a few false positives particularly around PETN. There's two available sizes of desiccant. You have the small three week disposable. These are discarded without any recycling. Fixed installations use a six month drum. This machine can only operate in either negative or positive IMS at any time. Negative for explosives, positive for narcotics, but not both concurrently. The Nickel-63 source decays with an average energy of 17keV. That's quite the low end for detection with most Geiger-Müller tubes. You may be only detecting the infrequent higher energy emissions. The source is quite spicy at 555MBq activity. An unfortunate design choice in a later model put the ionizing source moronically external and easily accessible behind a screw plug. Standard operating procedure requires HAZMAT response should this be unscrewed.
The basic principle of these systems is that a sample is ionized by electron impact fro the Ni63 source, at atmospheric pressure, and then accelerated in an electrostatic field gradient in the presence of a background gas, typically pure nitrogen (but other gases can be used to be more specific for some materials). Depending on the size of the molecule the speeds will differ, heavier ions are slower, and also the interaction of the ionized material with the background gas will affect the mobility and transit time in the of the ions in the drift tube field. Highly reactive molecules will be affected by the presence of the background gas and will be slowed more than less reactive ions, hence using different gases in the drift region will allow for a better discrimination between different molecules and classes of materials. The result is a complex spectrum of arrival times of different molecules at the detector. Some commentators have correctly stated that these systems are not necessarily perfect and can give false positives in many cases, which however is better than giving false negatives. But they are damned sensitive. Having worked in the past with explosives (legally and professionally) I have always been at great pains to ensure that I never used the same clothes or tools or bags which I used in the presence of explosive materials after I was was once asked (at gun point) the airport "Sir, can you please explain why your bag shows traces of TNT !!!!! "
You can reactivate them with ammonium carbonate for the narcotics mode. The explosive mode requires methelene chloride. The ni63 is needed because you need the potential to ionize the target but not the ammonia carrier gas.
I used to use one of these when I worked at an airport, looking forward to seeing the teardown as I always wanted to play with it more. Of course considering the post-9/11 price of one of these pieces of equipment, doing anything other than the standard procedure was frowned upon
They probably used a radioisotope source for a number of reasons, the one I suspect was that the original design and research predating this machine was probably demonstrated in a lab with Ni-63, redoing all those tests and gaining the certification for the result to be considered evidential likely would have been expensive and time consuming and would also benefited their competitor if they did it. The Ni-63's decay is also a fundamental property of the laws of physics so you pretty much don't need to calibrate it whereas an electrical system would need a lot of calibration and fault detection support circuits. And of course with most equipment like this there's many patents you have to get around and it's possible that there's a patent for doing it electrically they didn't want to license. There's also the chance it was to intentionally prevent an individual from buying one of those devices as you would in some regions need a license to buy and in particular export it. The one thing I've never understood with those machines is why are they used pretty much exclusively at airports? In the grand scheme of things even those older units are very sensitive to pico-grams of drugs and were cheap and small enough to be put in the back of a police car yet instead police dogs are still used today which are very expensive, require a lot of logistics and training and have the problem of being unreliable and the enormous problem of being very easily induced by the handler to give a false positive. I was also expecting to see some tamper devices in this machine like a bump sensor to invalidate a test if the user hits it trying to induce a false positive (or false negative).
Police dogs (at least in the US) are basically a farce. Yes they can do their job very well, but the value is in the handler who can interpret anything as a hit/positive indication from the dog. Basically if a dog gets brought out to sniff your car/whatever, and the police /want/ in, it's their golden ticket. That's presumably why they don't use those machines. Ie, the false positives are part of the appeal (also the dog supposedly has better... range? I guess is the word). Also I presume there's regulatory issues with police cars driving around with radioactive sources in the back of them (but I'd imagine that's easy enough to get around if you just had a few dedicated units/cars with them). In a slightly less farcical way, police dogs also have multi-role utilities, they can do more than just sniff out drugs.
Are these used evidentially? I think they’re just a defensive screen: it would then be necessary for more refined detection analysis/recording for legally acceptable evidence to be presented?
@@chriswalford4161 Not sure what word to use, I don't mean evidential in court to demonstrate any substance was present but for the test result to be considered valid 'probable cause' for a search, you need to have a reliable test for the search to be legal (flipping a coin to decide on a search is illegal in many places).
@@nexaentertainment2764 Yea police dogs really just seem like a probable cause generator, it's funny watching footage of them being used, if the dog doesn't alarm to a car they just keep walking the dog around until it does or just bring out another dog or just flat out give the dog a cue! Some places have rules about that sort of thing but most don't. The source isn't super powerful, many vehicles in the construction industry drive around with sources a thousand times more active for X-ray stuff. Although I suspect they would only put them in dedicated cars like K-9 units as not every car needs them and I would imagine they wouldn't survive a high speed police chase. I also question why police dog units are so common yet I've never heard of a sniffer dog in a fire department HAZMAT team, I know they use this ion substance detectors instead (presumably if they're called to something they don't need to get probably cause).
The three reasons I can think of for the nickel ionization source are 1) it is a relatively delicate way to ionize things, and this machine does not appear at all equipped to deal with fragmentation spectra. A high-voltage "negative ion source" literally blasts apart the molecules. 2) the high-voltage circuitry necessary to do this 'the right way' would have been inconvenient to implement both in terms of electronically as well as in a way the didn't generate enough ozone to do chemistry severe enough to disturb the readings (not to mention that ionized atmospheric gasses could swamp the signal) and 3) 63Ni is just easy to come by. Edit: I think it would be generous to even call this a mass spectrometer. It looks more like an ionization-detector gas chromatograph with a single-quad selector added at the end. This is essentially 1950's tech, made (marginally) more affordable by the modern age and the limited use case scenario for which it was designed. It isn't even something that I would call a GC/MS, and that is... kind of disappointing, honestly. Thanks for showing this, though. I always wondered what was going on inside these things.
P.S. another thought, discrete ionizing events spaced over time might make it easier to deconflict mixed signals from contaminated samples, in other words if you charged the whole substance in a classic GCMS you would get a simultaneous rapid flow of all ions arriving at the sensor conflating all substances and their mass charge products. However if you ionize with a radiation source you get discrete events where you have temporally separate and discrete detections of mass charge that can be more easily associated with a single ionizing event on an individual molecule. Doing this in conjunction with the right processing you can build a more reliable profile isolating contaminants from substances of interest.
Absolutely stupendous, as usual. I can't tell you how much I've learned about physics and engineering just from watching channels like this over the years, and this channel in particular. Would love to see the Ni63 source turned into some kind of permanently glowing neon tube or made into a betavoltaic battery. Mind those bremsstrahlung if doing the latter, natch. So glad to see this channel 'alive' again.
The reason for the use of a Ni63 source for electron impact Ionisation is simple: This product operates at atmospheric pressure and hence a hot filament electron source would burn out too fast and have limited lifetime and stability.
Lovely teardown. Two calibration sources for gas analysers I purchased on auction had the sources removed before the units were placed into storage years ago. That was nice of them when they were thinking they might be used later. The manual on these gas generators mention that leaving the source of the calibration gas SO2 in this care in the machine when switched off for longer than a day was very bad for achieving low baselines in future. Leaving it in for a week without flowing air would permanently contaminate the system with calibration gas. My sources would have been small tubes or vials with a calibrated thickness and area Teflon diaphragm that would diffuse the gas out at a known rate at a known oven temperature. Crude but quite common it seems. Certain compounds are easier to detect with certain technologies. This shares a lot of technology with gas chromatograph but is a special purpose ion detector. The ex sample wouud likely be sone nitrogenous compound Not sure what the recreational compound sample would be, perhaps chlorine compound for the many hydrochloride salts that are common, dunno. Lovely bit of gear. The rad source has a practical lifetime and will be safe in a couple of hundred years or so perhaps. I expect that delivering it to the local radiation monitoring office with a make, model and serial or licence number for the source would allow them to check it off the list of lost sources if you no longer have need for it. They are hard to come buy as they have to be returned when decommissioning a device or if sold he new site has to get licenced. It would be nice to have a working and maintainable GC to play with but the running costs can be high. Depending on the column and detectors you may need pure Nitrogen or ZeroAir to keep it purged and then Helium or Hydrogen as carrier or fuel gases. The HP units are quite common with FID detectors but you have little idea of condition before and during storage. I have a dead PSU portable Voyage PhotoVac unit with a UV ionisation detector that has an option for a Ni radioisotope ionisation detector that was I think for sulphur compounds that the other detector was blind to. These units were advertised for use in soil remediation monitoring in super fund clean up locations. Near impossible to get any software or compound libraries for these old units. Been waiting to get an EPROM reader to see how complex it is. Single processor and crude user interface. Also everything is fully custom to keep the size down so no chance of buying new columns when they age or fail. Might still try and wake it up one day if I can find a easy source of ZeroAir or lab grade N2.
Others have mentioned the long term calibration stability of the beta source being a benefit over electrostatic approaches, but another complication is that EMI and ESD standards for concourse-side equipment are far more strict than typical environments, so it may well have been cost prohibitive. The ESD potential may also have been problematic if they were going for certification in explosive environments.
63Ni ion sources are still common when it comes to this kind of "field deployed" IMS systems because they are highly predictable, since the primary current they produce is virtually not changing with a half life of 100 years basically maintenance free, and require no additional electronics / high voltages. The beta radiation induces basically atmospheric pressure chemical ionization (APCI) by ionizing nitrogen as primary ions which then undergoes further reaction cascades (depending on the water content in the drift gas etc.) which transfers the charge eventually to the organic analyte molecules. The alternative to the 63Ni would be a "real" APCI source as commonly used in mass spectrometry, which use a corona discharge on a sharp needle for primary ionization. Such sources (and the needles in particular) are everything, but *not* maintenance free, since the needle tips gets wear from the plasma and the discharge current has often to be controlled by hand etc. Other alternatives would be RF or DC plasmas, a RF-dielectric barrier discharge for example. One can find plenty of different plasma sources used for such sources in the literature, but none of them are exactly easy to handle or maintenance free. RF plasmas are probably also not that well suited if electronic interference is a thing to consider.
Fantastic video as always! I wonder if the calibration substances are molecules that are in some way structurally similar to those the instrument is to detect? The only other option as someone noted, was to use a mixture of the real substances themselves, surely a tiny amount, mixed with an inert base, would entail no more red tape than including a Nickel-63 source? It would be interesting to have a mooch through the Patents on these devices.
Started to break out in a cold sweat while the ceramic and gold holder assembly was taken out from heater cavity(reference to taking detonator from a torpedo ,like in the movies) very cool apparatus !
I once had the misfortune of reusing a duffle bag that I had stored ammunition in and went through an airport with it. Next thing I know I was being surrounded by TSA agents, armed security, and two guys that had jackets on that said explosives experts on it. These things work pretty well by my anecdotal evidence.
I've often had the thought that someone could cause an enormous security alert by just surreptitiously contaminating hundreds of people's bags with a nitrate salt, since that's no doubt something these devices look for. That could easily be done with some fertiliser of an appropriate type dissolved in water and put in a water pistol.
Back in high school my friend was flying to a Track & Field event with his team. Trouble is, they'd all run across a freshly-fertilized field the day before. All their gear was stained blue. Predictably, they were all asked aside at the airport.
On the other hand, I've been with someone who had their belongings scanned. They got through the test, only to show me (after getting through security) they had some MDMA on them...
This instrument is loaded with Swagelock brass fittings. Very high quality, not inexpensive. My company used a lot of these on medical equipment I designed.
Just loved the pile of bits in the final frame - especially the mug sitting there innocenty! The detector assembly is beautiful and deserves to be framed or mounted in some kind of display cabinet rather than getting lost among a drawer of similar bits in the workshop... Something
The desorber is the part that heats the sample and volatilises the sample and lets it flow into the system, the SCC is the secondary combustion chamber where any excess off-gassed samples are destroyed using heat (and potentially a catalyst, which is probably the tube with the foam in it, although I would have expected it to be heated).
That is very interesting. Do you know why the SCC was added to the system? Why not just using only an exhaust scrubber, which is present anyway to capture the combustion products?
In this case I'm not entirely sure, but probably to break the products down so they're no longer hazardous. The side products after decomposition are probably far easier to scrub/capture as well (with explosives most of them will break down into water, nitrogen, and carbon dioxide for example which are essentially harmless and can safely be vented to the atmosphere).
Remember that there's almost certainly a massive excess of oxygen present as the sample sizes in question are minuscule compared to the volume of carrier gas, as such incomplete combustion is unlikely so scrubbing will mostly consist of the catalyst destroying unwanted/hazardous side products (nitrogen oxides/carbon monoxide/etc) which can't be directly vented to the atmosphere. TLDR of it all: Designing a filter to scrub such a wide range of completely unknown compounds in such tiny amounts would be a complete nightmare (and would presumably require regular servicing to replace said filter), but breaking everything down using heat into smaller molecules which are then catalytically converted into harmless gasses is relatively straight forward. I would love to know what type of catalyst they're using though as it didn't appear to be heated, catalysed reactions are *always* sexy but low temperature ones? doubly so.
The detector electrode being that shiny probably has something to do with coronal discharge. To prevent charges from gathering and flying back off of the detector surface off of some kind of metal whisker or something, precision high-voltage surfaces must be as smooth as possible to prevent coronal discharge.
Have one, bought it at a government auction site for $27 canadian. Mine has a failure in the heating unit but have not played with it much and don't have a manual. Sweet tear down, saved me time.
I can only imagine how many completely totally random air travellers this thing inconvenienced in its life. My last experience with one was flying out of Whitehorse. The screener was a very new Canadian and didn’t know what random meant. She did the whole passenger manifest while smiling and reading the “randomly selected” verbiage to each one.
It's likely that the calibration compounds *are* narcotics/explosives - but in a form that would be either a precursor to widely used substances, acting as an impurity, or it would be the actual material, but in a mechanical/chemical form that would make it both unusable and unviable to extract, to avoid the red tape. That, and the amount is almost certainly minuscule.
Fascinating look at this tech from 20 years ago, i would love to see how it has progressed on the newer models. I bet it is much condensed and simplified. We have two newer machines where i work, i would love to see them in bits too! They are very sensitive and false positive all the time much to our dismay!
One of those things went mental on me on return home. Lights and sirens and all shit. Apparently my bag had traces of all the drugs🤷 otherwise clean. There was never any drugs in there. Massively hyped and then disappointed guard.
Could be calcium sulfate desiccant with indicator (Drierite). Turns pink when its moist/used up. Could actually be re-used if heated to 210C, but, don't think the air is getting that hot inside there. and you said it uses a bypass loop. Design of this is so much better than that last unit.
that thing sucks at detecting weed, I live in Canada so legal cultivation and recreational use of weed, I grow and smoke my own weed on a daily basis and work as an aircraft refueller at my local airport and have my hands swabbed and tested with that machine multiple times a day, never has it ever pinged on weed for me lol. I am also an avid sport shooter, member at my local gun club, it HAS pinged on gunshot residue for me even 3 or 4 days after a trip to the range lol.
im surprised it hasnt registered THC, since that is actually not that hard to detect compared to the numerous gunshot/bomb residues. but yea this is mostly security theater than real capability. im a chemist using some similar ish science tech for detecting compounds and these are really not sensitive enough to relibly detect the tiny amounts from a simple swap i see the airport crew do. in a US airport i once had to open my bag because it detected smth, which turned out to be a package of rice :P
Funny you say that. I put some actual pot in one of these and the portable one called a vaportracer and got no hit on it. Unlike this guy i got them up and running, found out if you switch it to service mode it has a raw tof table output. Bingo benchtop mass spectrometry for cheap. 🤓😎😁
I don't know what sort of energy is required for the electrons this thing uses, but that directly correlates to the voltage you would need to use to accelerate them. They may have wanted to avoid the cost and size of a power supply providing voltages in the 100kV range. The first beta decay I lookwd up just now peaked at 0.2 MeV, which would require a 200kV acceleration potential.
one doesn't need high energy electrons to ionize molecules. 80 eV is about optimal. In this device, i think, the radioactive source creates ions primarily in the air, which stick to the molecules of interest, making them ionic. I wonder if a corona discharge can be used instead...
Awesome!! The pneumatic coil is to cool the air and condense any moisture that was in the air down into the evaporator you mentioned. Everything about this was very well thought through and assembled- minus the printer lmao
Stuff like this was being assembled as fast & crudely as possible in those days, to fight the "war on terror". That might be why the parts are in there are so obsolete for the early 2000's. In 20 years though, those machines never detected any bombs or drugs. They were just deterrents.
Having investigated the complex ion chemistry in the ion source and drift tube region for a living a few years now, i am not surprised at all... It is hard though to get *real* information about chemical interference, cluster chemistry mitigation etc. from the vendors.
I know your desiccant bottle is shot, but that cobalt chloride can be regenerated easily in a toaster oven at 120-150 C for about an hour or two. Just dump it out into a glass pan and refill with a funnel. It will turn blue when you are good to go. If it turns black, your oven is too hot.
You can resell that square speaker of the logic board to some poor guy that owns a later model Porsche. They often go bad as the warning sounder in Porsche clusters.
And for those who wonder; its not a conincedent it doesn't work, its has been made not to work. I even think there is laws for that for this kind of equipment.
I don't understand why everyone is making a fuss about the radioisotope source. You can buy smoke alarms off the shelf which have a radioisotope in them, nobody makes a fuss about that.
Because it all depends on the activity and type of radiation they give off. Some can be lethal, some are quite 'harmless' unless ingested and some are indeed fairly safe such as the Am sources in smoke alarms.
I believe the reason they use a beta source for the ionisation is because it doesn't need any preparation to be done to the sample, which is exactly what you want for something that needs to be quick and usable by a non-technical person, like this. Normally for mass spec you need to dissolve your sample in some solvent to get it into the gas phase for it to be ionised and shot off down the system. Instead of all that you can just point a beta source at the swab you load into the system and any substances on it will just be directly ionised by the beta radiaton, and I imagine the large amount of energy imparted also helps to vapourise whatever you've got on the swab.
Ah, they also use ion mobility spectroscopy rather than traditional MS, this can work at atmospheric pressure which is another huge advantage. And beta radiation will work just fine to ionise the sample at 1atm, something you can't do with an electrostatic system.
@@otherunicorn Yeah, I see that now, probably should have watched the video first, eh? That just leaves the ability to ionise the substance molecules at atmospheric pressure. It's important that you directly ionise the sample, an ion generator (ionic breeze type!) will interfere with the mass of the molecules you're trying to detect, since you're adding extra atoms to it with your reactive ozone molecules or oxygen radicals or whatever.
@@jhonbus To be honest: Not really... the 63Ni source induces ion chemistry which is virtually the same as with atmospheric pressure chemical ionization (APCI) with a corona discharge or plasma as primary ion source. The analytes are not directly ionized, what happens is that the nitrogen, which is present in vast excess, is ionized and then a chemical reaction cascade starts, which transfers the charge to the analyte ions (hence "chemical ionization"). There is always also radical and additional ion chemistry going on in the ion source, but generally those systems just live with that and try to mitigate chemical interference by clean drift gas etc.
Looks like the big canister with filter medium with the quick connects had a datecode of 2013 - so it is some sort of consumable as you can expecy things with activated charcoal to be.
it is essentially a very high end smoke detector.... the inside looks like what you find in a Mass Spectrometer, like an ICP-MS. Essentially what you would have at the back end of CRT tube, just a bit different.
👍 Excellent and thank you! This piece of kit captured my interest as I was tested a few times over years of air travel. Designing sensitive lab analysis equip for use in the field by minimally trained folks is quite a challenge.
The printer option looks interesting,. Regs require logs of calibration tests and alerts so i wonder if this was added to provide physical printed logs of daily calibration and activation alerts.
I wonder if you could increment some bytes in the battery backed SRAM enough to get the checksum to pass? Would be interesting to see it try and boot up. I guess it’s a bit too late now :P
I believe Mike is located in the UK hence the NRC / NRPB is not in their jurisdiction but he equivalent UK body will be so very much. I have serious concerns about he way he is going about this and how he is handling the source. Having worked with Ion Mobility Spectrometers containing these sources my self, I am inherently familiar with he technology.
Yep these things are a pain in the ass to keep running. Also there is nothing in the software to tell you when to do it, it just fails to calibrate once they are no good.
My Canon 100-400mm mk II lens often would trigger a manual swab and search with one of these at the airport. Worth it to see the lens on the xray though. Haha The CN Tower in Toronto uses this tech on people before ascending. They look like walk though metal detectors, but blow air on you and detect explosives.
When i first joined my current company we had a product they were upgrading in the field by having field technicians using a dremel to cut a slot to insert a thermal printer. I found out years later when referencing that there is an i2c bus brought out to an unused factory test connector on the back they could have just used.
I imagine that the reason for not using an electrical ion source could be that atoms from the source electrode would be slowly emitted and would mess up readings?
wild how under all that bog standard industrial electronics stuff, when you finally get to the part that does the wizardry that they do not want you to take apart, it looks like some kind of atompunk 50's space raygun wonder! It is really not in any way designed in the same fashion the rest of the box is, like some boutique esoterica.
Customers doesn't care about how it look on the inside only the function and that the exterior is a perfect representation of the price. And also based on the cost of fex these things they would never dare to open it, which the manufacturer know.
Because it isn't a product of our current scientific and technological canon. You may laugh, but this is alien / antediluvian technology rediscovered. Take a look at the CPU of a quantum computer. Same deal. Old world tech has a certain "look."
electron guns need vacuum to operate, else the filament would burn out. for this reason and the general massive complexity and headache involved with vacuum tech they use a radioactive source i beleive.
Yes its much easier but its also a severe headache of all the permits needed and special conditionally designs due to the radioactive material and so on.
I been still thinking of this video for days after. Smiths also had a metal detector-style walkthrough sniffer unit, too bad you couldn't get your hands on the sensor unit from one of those. They used to be commonly used for explosives sniffing in places like the CN tower in Canada to gain entry, one place I know of that used them heavily. They didn't seem to catch on in airports due to all the false positives.
They may have used a radioactive source to allow the product to be deployed to areas with less reliable electrical supplies and operate longer off of a portable power supply
It''s a standard product with many variants including differential - easier to use the same casing than do one specially. The datasheet shows the second port as unused
My guess that the memory was blank is so ppl can't test if their new drug is detectable or not. I would not be surprised it that perhaps might even be something regulated or such.
@@mikeselectricstuff taste it to see if it's literally and not just metaphorically spicy! It would be super cool to see it put inside a glass ampoule and backfilled with a few torr of neon then sealed off to make a permanent (well, 100 year half life, anyway) nice orange glowing light source. Barring that you could make your own betavoltaic nuclear battery that would have WAY higher power than those other indirect tritium vial based ones you occasionally see people make.
Today system like these use IR light instead, if i'm not incorrect, so when the unknown substance is illuminated with that (its not only one IR wavelength) different substances will emit different wavelength back that is specifically to that substance which can be compared to a database where all illegal substances exists and get identified very quickly.
@@dtiydr seems like ratios and relative quantities would matter quite a lot. The biggest challenge with these systems is isolating the signal from the noise.