I was an engineer at Net Safety for over 10 years (a Canadian company in fact) - it's a blast from the past seeing the "Banshee" here! I worked on the electronics and firmware for every gas detector we designed from 2004-2015 except, ironically, this one - it was a rebranded product. We all had the same reaction to the looks!
Do you know much these cost back then? I work in instrumentation and got curious about this. Mostly because I've been realizing everything we quote is way more expensive than it actually is.
@@JohnDoe-rk4om I'm sorry, I don't... but you're correct about pricing, if memory serves many of the point detectors I designed had a BOM cost around $60-$90 (CAD) and sold in the $300+ range. To be fair a large amount of work goes into getting gas detectors to meet performance standards. Accurate & repeatable from -40 to +75 degC, can't allow water to get in when submersed to 1 meter, can't allow explosion to get out, but must be gas permeable enough to have a t90 response time of 30 seconds when the sensor itself has a t90 response time around 15-20 seconds!
@@toddphelps5030 Yeah that makes sense to me. Its the same with some machines we make too. Most is just standards / testing. That said, when I mentioned overcharging I didn't mean the price of the item accounting for revenue/engineering. I meant that I just started realizing most stuff I get quoted is charged much more than its actual 'msrp' value. Probably because I work for a really big company. I looked this up and saw that it was in fact around 300$ and just wanted to confirm because I've seen similar* stuff quoted at 1500$ Haha. Like I don't know why it never occurred to me to check before. For example, lots of transducer quotes I've found in the lab are around 600$ to 1000$. These are basic 4-20 mA pressure transmitters of 200, 3000 psi, etc. But they're actually around 300$ or less.
The principle of this type of protection is that they assume the thing will fill with gas and ignite, and the enclosure must not allow any flame to escape. (During the approvals process, they test this using either hydrogen or acetylene + oxygen, with expensive gas analysers to get an accurate mix to meet the standards) This is why it has a long, tight-fitting flange on the main enclosure joint. The terminal area has less stringent requirements, so no flange, but also no active components. I think the external glands ( called line bushings) specced for use with these are designed to be gas-tight and not allow gas to go through the cable, hence the lack of per-core sealing here - they typically have a bulkhead filled with epoxy, with the wire stripped bare where it passes through the resin. This is not the same thing as intrinsic safety - with IS, the protection is provided by limiting voltages and currents by design, whearas explosion proof (Ex-D and Ex-E from my hazy memory) is used where this is not practical due to power requirements. The soldered fuse is not uncommon - a major part of design for Ex approvals is not so much designing it to be safe, but designing it to be easy to prove it's safe. It is standard practice to include fuses, zeners etc. that have no chance of ever acting in normal or even fault conditions, just to make it easy to compartmentalise parts of the circuit to make it easier to evaluate for approvals. Including a fuse is a simple & cheap way to prove that the current can never exceed a certain amount under any circumstance - the standards define how much current can pass a fuse of a particular rating, the number 1.7x rings a vague bell. It also reduces the risk that some idiot replaces the fuse with the wrong value ( "less danger of it blowing guv....").
Brings back memories of designing and building Class 1 Division 1 gas detectors for drilling rigs. Equipment is still in use and no one stuck a screwdriver into the metal flange, made me cringe when he did that.
I don't think the connection area has any less stringent requirements. If you look at the flanges you'll see plastic washers at the screws which will be specced to keep a deliberate air gap. The purpose of the wide flanges with a calibrated gap between them is to allow any gasses from an internal flame/explosion to escape while cooling them to below the autoignition temp of the atmosphere they're designed to operate in. If the enclosure were properly sealed and an oxy-fuel mix ignited inside you'd have a bomb. That goes for Ex-D anyway. Ex-E enclosures are generally held to a '30 second' standard where they need to prevent the intrusion of gas for 30 seconds. These can be cheap sealed plastic enclosures and are generally used in systems where there is detection like this and a shutdown in case of gas detection. You'd never find Ex-D enclosures in Zones 0 or 1 as there is expected to be an explosive atmosphere during normal operation.
There is no point to make an enclosure that can confine explosion, it would be better to just fill the empty space inside to eliminate the gas volume that can ignite. This thing look like a toy to amuse inspectors who otherwise would not allow the device due to complete ban of electronic on a facility.
I was thinking the soldered fuse might be a design choice. Definitely stops someone from replacing it with a larger fuse. Thanks for sharing your expertise on this. Very interesting stuff.
I design industrial explosionproof electrical systems that something like this would be used in. Aside from the obvious heavy duty nature, there is a whole field of study you could jump into regarding flame paths through all the seals, gaps, conduit entries, etc. That is a HIGHLY engineered piece of equipment and probably costs as much as a house! Good on ya for getting one in your hands!
@@Ariccio123 Yes the seals are designed to fail in a deliberate and slow manner, so that they equalise the pressure over a few seconds to minutes, but at the same time do not allow any flame front past until it has had enough energy pulled from it into the long labyrinth path of metal to cool down below autoignition temperature. After the internal bang you can have soot streaks, but the outside will not ever have gotten any flame escape, or any gas over around 70C, which is below the autoignition temperature for quite a few of the more popular fuel gases used in industry and the home. Has to contain, and not allow ignition of the external explosive mix.
@@Ariccio123 There are flame arrestors that you can put in a pipe carrying an explosive gas mixture that prevents the flame from passing through the arrestor. No seal at all, the gas goes right through it but a flame can't get by. The thing is narrow passage, high conductivity and large thermal mass so a flame gets cooled down. They only work for a limited time of fire on one side.
You also need to put an eccentric motor vibrator inside that triggers when the countdown reaches 5 seconds or thereabouts, so as to intensify the effect.
This construction brings to mind the commercial nuclear plant radiation sensors mounted within the concrete reactor containment that had to survive a LOCA (Loss of Coolant Accident). The sensors needed to survive not only the pressure pulse of the explosive release of steam, but also the more troublesome thermal heat pulse, not to mention the radiation pulse it was intended to measure. Those same standards applied to everything within the containment connecting to the sensor, including conduits, cabling and most importantly the connectors. The main approach was to use lots of secret-sauce epoxy everywhere, so the housings themselves didn't need to be built so robust, which particularly mattered for the sensor, as excess material affected its sensitivity, and a large neutron release could make the housing itself radioactive. Even the heat-shrink enclosing the connectors was beyond special, where a 10 cm length would cost $200. The coax was an entirely different story, as no manufacturer was willing to certify their coax for LOCA. So we had to do the certification ourselves. While we had access to a physical LOCA simulator for temperature and pressure (which sounded like a bomb going off), we did not have one for radiation. The highest radiation flux we could find was behind the beamstop of a small linear accelerator, where we made a small closet and hung coils of the coax candidates, to be pulled out and tested/characterized every month or so, along with measuring the total radiation dose. To keep the cabling to a minimum, we sent 2-4 KV down the coax, with the radiation level encoded on the return. During the LOCA event, the pressure and temperature pulses would significantly change the capacitance of the coax, an effect the overall system had to both survive and account for with great precision. The coax runs could be up to 1 km in length, to get the measuring instrument far enough away from the containment for it to continue to function through the event.
Hello :) In the factory where I work, there is a unit where we produce ethyl alcohol. We use Ɛx rated appliances there. Many of them have similar soldered fuses. When I asked one of the manufacturers why they were like that, they told me that it was a requirement of the insurance companies and a policy of our group as a customer. The idea is that in the event that this fuse burns out, the device should not be repaired, but replaced with another one. It's simply not worth the risk of putting an appliance that has had a technical problem in front of an explosion that will surely cause massive damage and kill people.
Probes into the sensor heads are there to have the heater blocks screwed in instead of the blank probe, to heat the actual sensor itself in use in icing conditions. Self cleaning probably uses those probes, and then a separate port into the case that provides the air pressure for cleaning, via stainless steel pipes and a spiral tube that connects the ports to the top. That is why there are 2 recesses in the probe, one for the cleaner, not fitted and drilled to spec, or the heater, fitted to all but in temperate use only the dummy heater block.
@@tinkerwithstuff timer certainly does not set off anything in case of event (but the moron actuating the lights when smelling the gas to have a look if thereis anything to turn off certainly will)
Worked on 'explosion proof' fans and such in the Navy. They aren't completely 'gas tight', but the idea is that any explosion inside won't ignite the atmosphere around them. So for example, submarine battery fans (H2 hazard) had to have very close tolerance fits. H2 might actually get inside, but if it ignites the flame can't 'blow out' through any of the tiny cracks/ crevices. Sort of like how a steel screen placed over a bunsen burner, the flame won't go up through even though hot gases flow up through the screen. And of course the casing is strong enough to not rupture if the inside is filled with the 'perfect' mixture of explosive gas/air. So that interface cable might let gas seep along it between all the individual conductors, but that's fine.
These devices rely on the quneching effect of a long, narrow and cold high thermal inertia, low thermal impedance "gap". All the joints therefore have big "lands" ie characterisitically long areas between the tight fitting ally halves, so any flame that propogates through that area is quenched during it's passage. The O ring provides environmental sealing but does not seal the unit against high pressure faults
At 16:00 you mention seeing the home-made optio-isolators before, but didn't remember where. They were in the electric fence power supply you cracked open a few years ago.
I'm puzzled as to why all the isolation between the transducer and the processing/I/O though? There were also a heap of what looked like TVSs on the sensor side too. I'm used to seeing isolation & protection on cables going *in* to protect against transients from lightning etc. To improve SNR from the transducers? Or to prevent a fault on the data cable from passing any electricity to the transducers and potentially providing an ignition source?
@@rkirke1 they may have just gone nuts with the intensity safe thing. I used to build an IS device at my previous job (sewer flow meter), and every power supply had 3 diodes to short the power supply in the event of a voltage spike. Also, this was a battery operated device that had to last multiple months, so there were like 15 beefy diodes on a device that draws a max of 100mA. As far as the device in the video though, it's possible that it was using that distance of isolation just because it's easier to assemble or something. Though that would require the engineers to actually talk to the lowley operators for DFM, and that is a stretch.
Ya need to have a big motor and weight in there, so when the counter reaches 0, it vibrates like mad, dancing across the floor, then stops, and a little voice says "bang."
Would be cool to turn it into a big thermal detonator from SW. You trip a sensor when you walk by it and it starts to glow red from the four pods, and makes the sound of a TD, and then starts counting down. Could scare someone new to his work area. LOL
Yeeep!! As soon as the movement stops it can add back a suitable remaining time... Bonus for a eerily calm womans voice "Danger avoided... Enjoy your day!"
You will probably find the TO220 devices on the heatsink are the heater, for preventing icing in cold climates. Fuse is soldered in so people can't replace it with a wrong item reason is:. That opto isolated area is all about limited energy so there's not enough power there to generate a spark at the microphones in any possible conditions. The power will get across there via that fuse then there will be zeners to limit voltage and blow the fuse. There is also a mandated clearance distance around that intrinsically safe circuit, which is why the homebrew optocouplers exist.
"Banshee 343" - Is the name of this a video game reference? The Banshee is a vehicle in Halo, and 343 is "343 Guilty Spark" from Halo. Halo series is now looked after by 343 industries.
You have the explosion proof issue backwards (I have sold industrial electrical equipment for over 40 years and have sold thousands of EX rates pieces of equipment).. They are designed so that if there is a failure inside and ignites the gas inside the device the flames and or explosion is contained and wont ignite anything outside the device.. If there is a breather it will have a very fine metal wool inside to prevent flame propagation (If they made all their own components they could have hid the breather in the cable connector). The inside volume is usually very small to limit the volume of flammable gas.. Less gas, less internal pressure if there is a fire or explosion inside. The volume of this device is huge thus the extremely heavy walls.
Looks like it has been dropped at some point. The posts holding the internal PCBs had snapped off which is why there were so many crinkle washers loose inside. Along with a countdown timer you need to add some accessible wires that can be cut to stop the countdown (but which colour should be cut? red? blue? green?) and if the wrong one gets cut it lights a small pyro to scare the bejesus out of you.
Yes you HAVE to make that display into a countdown timer, complete with piezo speaker that makes the classic "pip - pip - pip" sound that all bombs make in the movies/TV shows like MacGyver :) Perhaps you could even get pretty cluey and when it reaches 2 minutes left, include a capacitor charging sound (i.e. detonation/firing circuits charging up!) Yes it does look like a WWII sea mine!
Someone has probably mentioned it already but on page 22 of the manual, the empty space, between the sensor houses, is described as "pump compartment". Also, on page 46, an "H2S pump" is listed as a spare part.
There are some much less beautiful sensors equipped with IIoT, which also detect the ultrasonic sound of water pipes leaking. To increase the precision of the detection, they are used in large numbers in a mesh network.
A few years back I built clock which would read the correct time except that the seconds would count down. I started making a case for it from PVC pipes but figured it little might cause some panic so I never finished it. But maybe sounds like a good project for your case.
I have an empty high pressure gas cylinder that I really want to weld some fins on, paint it military green and half bury in the front garden. I'm just worried I might end up with the police or bomb squad knocking on my door!
That housing looks like steel casting, so more likely internal temperature sensor, used to both compensate for speed of sound, and also to activate heaters when the unit is in icing conditions, though the heaters look like an option not on this model.
I can see this thing be a perfect empty shell for either a movie prop or a "defuse the bomb" kind of gimmick that can be used in airsoft games or an escape room. You could put some RGB LEDs in the transducers together with a speaker to signal the bomb has detonated and the "defusing" team has lost. The IR can be used with a simple TV remote for code input to defuse it.
Needs a motion sensor so it starts the countdown when you pick it up. Then just leave it around the lab until someone picks it up for a closer look, “uh-oh, now you’re bu**ered!”. Then some secret way of manipulating it so it stops. Perhaps a certain number of deceleration events by smacking it on the table in various orientations.
Perfect sealing is not important. What is is preventing any flames or sparks from getting out. There is no gunk inside the cable because the cable is effectively acting like a spark/flame suppressor, wicking the heat out of whatever gasses may be attempting to make their way through long before they have a chance to ignite anything.
Those types of DIY optocouplers are very common in Fender guitar amps. They call them "dead bugs" and are used for the tremolo effect. The bulb is hooked to a phase shift oscillator and the LDR is used to dampen the signal.
thank you! This is adorable, this thing has been assembled by hand by skillful workers. I would retro-engeneer the counter and use it as a time display, add a MP3 player circuit in there and use it to listen to music in the bus :p
20 years ago our Cl2 plant was built new and the old Cl2 plant was decommissioned. Some years prior to that an operator was sadly killed in the old plant when he started a Hydrogen compressor and the local control panel exploded, H2 had crept from the compressor though the conduit into the cabinet and ignited when a start button was depressed. Thank God our cabinets are now pressurised with low pressure alarms on them.
QUALITY !! Investigate the component selection, solder quality, machining, materials, thermal management, and de-rated circuit biasing for a true appreciation of a very robust Design !
This totally needs some sort of IOT connection, perhaps to set the timer, to start the countdown and a webcam or lighting, all linked to the EEVblog website 🙂
It would be interesting to see if the cable bundle is stuffed with potting material at any point. On one hand, a flame could not readily propagate the length of the air passages from one side to the other; on the other hand, the blue sealant would be superfluous if gases are free to diffuse through the bundle.
I'd be keen to see multiple videos related to the "build a counter circuit" idea. Reverse-engineering in one, block-diagram design of the replacement in another, then schematic design, followed by PCB design and then final finished project presentation to round out a cool 5! :)
This Is an incredible find. I have only seen one similar device. That was in the early eighties. I had a neighbor who was a top notch nuclear physicist. He took me on a tour of Brookhaven lab ( and his experiments in the early 70's. This instrument is a result of the experimentation of that era.) Thank you for showing the basic tech. You should look back to the origins. I worked in the intelligence us Navy, in the 80's and this type of system was just being instrumented.
At first glance I was reminded of the on board fire extinguisher pods on USARMY Sikorsky UH60 Blackhawk Helicopters. I was looking for the firing squib ports on that bit of kit there. Thanks Dave !
I work with designing LNG plants and have never seen a ultrasonic gas detector before. Super cool! If there is a good leak, the sound can be really loud and not just in the ultrasonic range. One thing I always found interesting is that pt100 elements is one of the best ways of detecting liquefied gas leaks :)
"Banshee 343" sounds like folks from Halo designed the thing At first I had the same thought of being something used underwater...maybe sonar or underwater microphone for example. And you can go further than just a clock. You know you can!
It's surprising to me that there's so much empty space inside. I would have thought that having as little room for gases to accumulate would be a good thing.
It has to be spherical for maximum strength - which makes it hard to efficiently cram in circuit boards. You could have a stack of circular boards of varying diameters, but it's easier and cheaper to just make the case bigger and heavier.
I used to assemble troubleshoot and repair infrared light curtains ..which were safety devices used in machinery where limbs could get damaged ...and we got an order for an explosion proof light curtain once which we made with stainless steel .
I think you need to put the timer onto this with your kids so they can take it to school for show and tell to show the other kids what they and dad made on the weekend.
mmm... a nice countdown timer, flashing leds in place of the sensors, and a bleeper starting at 1 minute - getting faster and faster as it gets closer to zero. All controled via the IR sensor on the display board
@9.25 i think leak internal is no issue as both parts are in the exd box. The glands to go in and out have epoxy harderner and only strands are allowed. Sometimes cables are allowe but the a minimal length is required of a certified cable. In the usa conduit is used with a kind of concrete filling in y shaped pieces. All is pretty hard to service, ask me why i know :-)
With those rotary sw. one can set up the Scale for the 4 to 20 mA courrent loop . ( Pv for 4mA , for low value , 20 for Hi Value for ex.) In case your SCADA system has AMS included , ( for ex like Emerson DeltaV can have ) you get a lot of info from , or you can remotely set up the mesuring ranges etc on a nice interface on your Professional Plus WorkStation
When working in maritime electronics we used to have to travel by air, the same applies to things like ships Gyro's, (and your tools), airlines don't like them at all! I remember we used to test for intrinsically safe gear, you put it in a flammable atmosphere and try it!! We had to do it with radio's for the mines. (at Philips TDS). Good video..
I love seeing things like the numbers scribbled in sharpie on the female connectors coming from the potted area. It tells me that whoever manufactured that part of the unit wanted to keep track of which cables went where. The human touch that this adds to an otherwise decidedly industrial object tickles my brain in a fun way.
I would have thought it'd check the change in the speed of sound not the sound of escaping gas with those ultrasonic sensors, ergo the range specified being very specific.
Ex d "electronics" is neither really explosion proof nor is it gas-tight. It is designed so that an explosion/flame on the inside cannot penetrate to the outside of the case and cause an explosion there. So basically the nearly Standard electronics is packed inside a huge hunk of metal wich can withstand the blast of an explosion of the inside volume and the metal case has very small distance (and elongated) gaps through which a flame from the explosion cannot escape
16:19 Makes perfect sense to me though. Full of explosive gas and something move the shell but will make the fuse move a micrometer and produce a micro sized spark that is more than enough to ignite the gas. They do everything they can to prevent any spark to be created.
555 timer opportunity? Perhaps have several options for the display: time of day, temp of the case, count down timer. Count up timer. Maybe put a button instead of a sensor in one of the 4 ports.
Yes build the time board, plenty of room to put in a massive pouch cell and controller, using the IR receiver, along with a generic credit card transmitter, to do the count down. Use the one port to connect a piezo speaker to play the beeps, repurposing 2 of the connection wires for that, and the existing power connection for charging the pouch cell.
@@EEVblog Big 10Ah pouch cell is cheaper, and will do that no problem. Charge not needed unless you are really wanting, just leave out the discharge protection, or find a micropower one that uses less than the DW01 used everywhere, and the pouch will hold charge for the decade.
Make a widow for a solar panel to power battery then to the display? Thermometer with temp display? Time capsule with count down till open display? Or days since opened display?
There appears to be some missing components. The Self-Test documentation mentions a self-contained direct drive pump to provide compressed air that is forced through nozzles to create test sound. Where is that pump and plumbing?? A pump would also explain the seemingly excessive internal volume.
5:26 that kind of looks like a burst disc, which is a telltale for pressure waves in air. they can be calibrated to burst at specific pressures to indicate how strong a blast is (in terms of the pressure wave). i've never seen a burst disc hidden behind a sealed panel though. that panel over it almost looks like a GPS antenna, but its facing the wrong way lol
Banshee 343? Is that a Halo reference? 343 Industries is apparently named after the character 343 Guilty Spark, which would be fitting for an explosion detector, and it even looks a bit like him.... the font even looks like the 343 Industries logo
The relays aren't for heaters or other internal parts, they are exposed on the interface panel as external NO and NC signal contacts. Also, the shape and size of that pressure vessel is too damned similar to an implosion-type nuclear or thermonuclear bomb, except for the internal.
This , ( color ) indicates a Rosemount product . There , where the M1 stands, a HART comm ,little transceiver modul is missing ( Bell 202 modulation superimposed over the courent loop ) And yes , those products are expensive and very Reliable
i used to have to do temporary installations (days, to weeks, or months) of "explosion proof" CRT monitor housings. They were ridiculously heavy and cumbersome, and required their own compressed air supply to keep the housing at a higher pressure than the outside environment. Eventually we moved away from CRTs and the need for air, but they retained their weight and overall awkwardness. Better to have these working than to have an oil rig blow up though...
Hazy memory but I did a bit of Exd and Exe design for UK offshore back in the day (80's/90's), so this unit is Exd meaning it's explosion proof, i.e. Any major problems on the inside won't propogate outside. The cable glanding and the ultrasonic sensors, i.e. Anything that connects from the internal space to the external world has to be Exd rated. There were some types of cable entries/glands that had to be packed with an epoxy type stuff. It's all about flame paths. If I remember correctly, you had to declare and submit a BOM and layout drg for the internals in order to comply with the Baseefa/ATEX Exd rating before use. Once done, you couldn't drill any holes or strictly speaking change any internal parts. Exe (I.S. intrinsically safe) was different, that was all about limiting voltages and currents via certified interface modules including zener barriers, galvanic isolators etc. I did more design on the I.S. side. I remember designing and getting approval for a large Exe Lcd display and during the cert process being limited to the amount of total capacitance on my Pcb, the distance between components etc etc. With Exd, you are given a lot more lateral. Dave's unit it would have been one expensive puppy back in the day........! Ian
I suspect the led panel which you said had IR interface also, the chips on that board would be shift registers based on the number of cores in the ribbon cable attached to it..
At first I thought it was an airspace gyroscope. Anyway, I love expensive machinery teardowns, especially mil-spec items. Medical equipment is also high quality, way above consumer grade
You can use this sensors as a movement sensors, that will activate the countdown counter and maybe put a loudspeaker inside that will play something like "self destruction system engaged"
The fuse has to be soldered in because in case of a short circuit, you don't want someone to be able to replace the fuse and create a spark that could lead to an explosion!
That thing was brand new. They don't look like that after even several months in tropical or marine environments. Definitely want to see the countdown timer. You could add some red/green LED's where the sensors are for effect. I also like your idea of an IR interface to control it. You could get a generic TV remote to save some build time.
Each of the sensor housings has a cast-in orifice for actual pressurized gas to go through. I'm guessing they just did away with the extra pump and other items and just put the dummy plugs in place of it.
That would make an excellent egg cooker! Would fit perfectly on a kitchen table, in combination with the display counting down and a noisy speaker once the eggs are done.
That was an awesome tear down! And that would be so cool to have like an infrared sensor or remote controlled reset with a countdown. I'd love to see a project where you did that and just have it sitting on your shelf with it counting down LOL
The soldered fuse is no problem. The whole electronics are over engineered. If that fuse fails either the device is in the middle of a fire, over volted, or something seriously failed wich calls for an autopsy. In all cases there is no need for fuse replacement.
My question would rather be - does it still work? Some of those devices are replaced on a schedule regardless of they work or not to be sure that they aren't failing due to age. And rubber seals ages as well.
Couldn't find the price for this model new but I did find one used/weathered on eBay that sold for around $270 USD. A similar looking device new from a different manufacturer is asking $20,000+ USD which sounds about right. Apparently they never have to be recalibrated for the life of the unit.
Yap, would make a neat clock! I guess you can rotate the display board inside 180 degrees, so you can read it in sensors up position. Thanks for your videos!
Thumbs up this video and this pinned comment if you want to see a countdown timer refit project!
yes please!
Yes!! Definitely! It MUST have a timer!
Obviously it need a timer. But what will happen at 0? Or will you make sure it never counts down to zero?
Put a speaker in it
Hell yes!!!
This has TH-cam Dislike Button counter written all over it.
Finally, a proper case for a Raspberry Pi! :D
There is a company that makes Ex-D rated Raspberry Pis.
I would love to see one of these used as a case, but in a way that utilizes the 4 sensor nubs for something new.
Lol
I was an engineer at Net Safety for over 10 years (a Canadian company in fact) - it's a blast from the past seeing the "Banshee" here! I worked on the electronics and firmware for every gas detector we designed from 2004-2015 except, ironically, this one - it was a rebranded product. We all had the same reaction to the looks!
Do you know much these cost back then? I work in instrumentation and got curious about this. Mostly because I've been realizing everything we quote is way more expensive than it actually is.
@@JohnDoe-rk4om I'm sorry, I don't... but you're correct about pricing, if memory serves many of the point detectors I designed had a BOM cost around $60-$90 (CAD) and sold in the $300+ range. To be fair a large amount of work goes into getting gas detectors to meet performance standards. Accurate & repeatable from -40 to +75 degC, can't allow water to get in when submersed to 1 meter, can't allow explosion to get out, but must be gas permeable enough to have a t90 response time of 30 seconds when the sensor itself has a t90 response time around 15-20 seconds!
@@toddphelps5030 Yeah that makes sense to me. Its the same with some machines we make too. Most is just standards / testing.
That said, when I mentioned overcharging I didn't mean the price of the item accounting for revenue/engineering. I meant that I just started realizing most stuff I get quoted is charged much more than its actual 'msrp' value. Probably because I work for a really big company.
I looked this up and saw that it was in fact around 300$ and just wanted to confirm because I've seen similar* stuff quoted at 1500$ Haha.
Like I don't know why it never occurred to me to check before. For example, lots of transducer quotes I've found in the lab are around 600$ to 1000$. These are basic 4-20 mA pressure transmitters of 200, 3000 psi, etc. But they're actually around 300$ or less.
For some reason I expected this product to be in the $20,000 range.
@@user2C47 It probably was.
The principle of this type of protection is that they assume the thing will fill with gas and ignite, and the enclosure must not allow any flame to escape. (During the approvals process, they test this using either hydrogen or acetylene + oxygen, with expensive gas analysers to get an accurate mix to meet the standards)
This is why it has a long, tight-fitting flange on the main enclosure joint. The terminal area has less stringent requirements, so no flange, but also no active components.
I think the external glands ( called line bushings) specced for use with these are designed to be gas-tight and not allow gas to go through the cable, hence the lack of per-core sealing here - they typically have a bulkhead filled with epoxy, with the wire stripped bare where it passes through the resin.
This is not the same thing as intrinsic safety - with IS, the protection is provided by limiting voltages and currents by design, whearas explosion proof (Ex-D and Ex-E from my hazy memory) is used where this is not practical due to power requirements.
The soldered fuse is not uncommon - a major part of design for Ex approvals is not so much designing it to be safe, but designing it to be easy to prove it's safe. It is standard practice to include fuses, zeners etc. that have no chance of ever acting in normal or even fault conditions, just to make it easy to compartmentalise parts of the circuit to make it easier to evaluate for approvals.
Including a fuse is a simple & cheap way to prove that the current can never exceed a certain amount under any circumstance - the standards define how much current can pass a fuse of a particular rating, the number 1.7x rings a vague bell. It also reduces the risk that some idiot replaces the fuse with the wrong value ( "less danger of it blowing guv....").
We used to use Helium leak detection for underwater stuff.
Brings back memories of designing and building Class 1 Division 1 gas detectors for drilling rigs. Equipment is still in use and no one stuck a screwdriver into the metal flange, made me cringe when he did that.
I don't think the connection area has any less stringent requirements. If you look at the flanges you'll see plastic washers at the screws which will be specced to keep a deliberate air gap. The purpose of the wide flanges with a calibrated gap between them is to allow any gasses from an internal flame/explosion to escape while cooling them to below the autoignition temp of the atmosphere they're designed to operate in. If the enclosure were properly sealed and an oxy-fuel mix ignited inside you'd have a bomb. That goes for Ex-D anyway.
Ex-E enclosures are generally held to a '30 second' standard where they need to prevent the intrusion of gas for 30 seconds. These can be cheap sealed plastic enclosures and are generally used in systems where there is detection like this and a shutdown in case of gas detection. You'd never find Ex-D enclosures in Zones 0 or 1 as there is expected to be an explosive atmosphere during normal operation.
There is no point to make an enclosure that can confine explosion, it would be better to just fill the empty space inside to eliminate the gas volume that can ignite. This thing look like a toy to amuse inspectors who otherwise would not allow the device due to complete ban of electronic on a facility.
I was thinking the soldered fuse might be a design choice. Definitely stops someone from replacing it with a larger fuse.
Thanks for sharing your expertise on this. Very interesting stuff.
I design industrial explosionproof electrical systems that something like this would be used in. Aside from the obvious heavy duty nature, there is a whole field of study you could jump into regarding flame paths through all the seals, gaps, conduit entries, etc. That is a HIGHLY engineered piece of equipment and probably costs as much as a house! Good on ya for getting one in your hands!
Flame paths *through* the seals??
@@Ariccio123 Yes the seals are designed to fail in a deliberate and slow manner, so that they equalise the pressure over a few seconds to minutes, but at the same time do not allow any flame front past until it has had enough energy pulled from it into the long labyrinth path of metal to cool down below autoignition temperature. After the internal bang you can have soot streaks, but the outside will not ever have gotten any flame escape, or any gas over around 70C, which is below the autoignition temperature for quite a few of the more popular fuel gases used in industry and the home. Has to contain, and not allow ignition of the external explosive mix.
@@SeanBZA This! Good explanation!
@@Ariccio123 There are flame arrestors that you can put in a pipe carrying an explosive gas mixture that prevents the flame from passing through the arrestor. No seal at all, the gas goes right through it but a flame can't get by. The thing is narrow passage, high conductivity and large thermal mass so a flame gets cooled down. They only work for a limited time of fire on one side.
Doubt they made 30000 of them based on serial number if it costs as much as a house. A car is probably closer.
You also need to put an eccentric motor vibrator inside that triggers when the countdown reaches 5 seconds or thereabouts, so as to intensify the effect.
Or a big reaction wheel that speeds up to a high-pitched whine and then applies braking at T=0, sending the whole ball tumbling in a random direction.
And ticking noise!
I would have count it down to 007 and then stop...
That’s a golden idea!
Glad you were able to put your Finger on the problem…
This construction brings to mind the commercial nuclear plant radiation sensors mounted within the concrete reactor containment that had to survive a LOCA (Loss of Coolant Accident). The sensors needed to survive not only the pressure pulse of the explosive release of steam, but also the more troublesome thermal heat pulse, not to mention the radiation pulse it was intended to measure.
Those same standards applied to everything within the containment connecting to the sensor, including conduits, cabling and most importantly the connectors. The main approach was to use lots of secret-sauce epoxy everywhere, so the housings themselves didn't need to be built so robust, which particularly mattered for the sensor, as excess material affected its sensitivity, and a large neutron release could make the housing itself radioactive.
Even the heat-shrink enclosing the connectors was beyond special, where a 10 cm length would cost $200. The coax was an entirely different story, as no manufacturer was willing to certify their coax for LOCA. So we had to do the certification ourselves. While we had access to a physical LOCA simulator for temperature and pressure (which sounded like a bomb going off), we did not have one for radiation. The highest radiation flux we could find was behind the beamstop of a small linear accelerator, where we made a small closet and hung coils of the coax candidates, to be pulled out and tested/characterized every month or so, along with measuring the total radiation dose.
To keep the cabling to a minimum, we sent 2-4 KV down the coax, with the radiation level encoded on the return. During the LOCA event, the pressure and temperature pulses would significantly change the capacitance of the coax, an effect the overall system had to both survive and account for with great precision. The coax runs could be up to 1 km in length, to get the measuring instrument far enough away from the containment for it to continue to function through the event.
I am so deeply fascinated by all of this. Is there anywhere to learn more?
@@Ariccio123 Go work for Areva or some NPP regulator I guess :D
SO interesting! Thank you!
It's so awesome whenever humans get a chance to build something as robust as possible, as opposed to the mass-produced word of consumer crap.
And the Russians just don't bother.
Hello :) In the factory where I work, there is a unit where we produce ethyl alcohol. We use Ɛx rated appliances there. Many of them have similar soldered fuses. When I asked one of the manufacturers why they were like that, they told me that it was a requirement of the insurance companies and a policy of our group as a customer. The idea is that in the event that this fuse burns out, the device should not be repaired, but replaced with another one. It's simply not worth the risk of putting an appliance that has had a technical problem in front of an explosion that will surely cause massive damage and kill people.
Probes into the sensor heads are there to have the heater blocks screwed in instead of the blank probe, to heat the actual sensor itself in use in icing conditions. Self cleaning probably uses those probes, and then a separate port into the case that provides the air pressure for cleaning, via stainless steel pipes and a spiral tube that connects the ports to the top. That is why there are 2 recesses in the probe, one for the cleaner, not fitted and drilled to spec, or the heater, fitted to all but in temperate use only the dummy heater block.
Yep, there are two extra ports that are not drilled out.
"It's not a bomb it's a clock!" (also, Dave that would make the IDEAL kitchen timer for the Mrs...) 🙂
A bit on the bigger side for a kitchen timer, but yes! 😂
Alarm Clock!
@@MrJef06 An explosion proof kitchen timer! Gas leak in the kitchen? No worries, timer still works!
@@tinkerwithstuff timer certainly does not set off anything in case of event (but the moron actuating the lights when smelling the gas to have a look if thereis anything to turn off certainly will)
You've got to modify the display to count down... maybe it can do blanking too so it flashes when it gets to about 10 seconds or something too.
Don't forget to make it stop at 007 seconds
Dont hang that on your rearview mirror!
@@arikb , needs to have a Nixie display though….
Awesome prop... Yes, make it so :-) .
Worked on 'explosion proof' fans and such in the Navy. They aren't completely 'gas tight', but the idea is that any explosion inside won't ignite the atmosphere around them. So for example, submarine battery fans (H2 hazard) had to have very close tolerance fits. H2 might actually get inside, but if it ignites the flame can't 'blow out' through any of the tiny cracks/ crevices. Sort of like how a steel screen placed over a bunsen burner, the flame won't go up through even though hot gases flow up through the screen.
And of course the casing is strong enough to not rupture if the inside is filled with the 'perfect' mixture of explosive gas/air.
So that interface cable might let gas seep along it between all the individual conductors, but that's fine.
Wow thanks for your expertise on the comment that was cool information.
These devices rely on the quneching effect of a long, narrow and cold high thermal inertia, low thermal impedance "gap". All the joints therefore have big "lands" ie characterisitically long areas between the tight fitting ally halves, so any flame that propogates through that area is quenched during it's passage. The O ring provides environmental sealing but does not seal the unit against high pressure faults
TIL submarines use lead acid batteries.
@@user2C47 lead acid batteries produce hydrogen when charging. i have seen 2 car batteries explode due to hydrogen and a sparking battery cable.
H2 would be one of the very very explosive gases . acetylene is another. must have the highest level of protection.
At 16:00 you mention seeing the home-made optio-isolators before, but didn't remember where. They were in the electric fence power supply you cracked open a few years ago.
when lookign closely OP1-4 are differently oriented as OP5, maybe 1-4 are the selectors for the muxers and OP5 is the return path for the signal ?
It was EEVblog #1277 - Electric Fence Controller Teardown th-cam.com/video/2LuWr25xgzE/w-d-xo.html
I'm puzzled as to why all the isolation between the transducer and the processing/I/O though? There were also a heap of what looked like TVSs on the sensor side too.
I'm used to seeing isolation & protection on cables going *in* to protect against transients from lightning etc.
To improve SNR from the transducers? Or to prevent a fault on the data cable from passing any electricity to the transducers and potentially providing an ignition source?
@@rkirke1 they may have just gone nuts with the intensity safe thing. I used to build an IS device at my previous job (sewer flow meter), and every power supply had 3 diodes to short the power supply in the event of a voltage spike. Also, this was a battery operated device that had to last multiple months, so there were like 15 beefy diodes on a device that draws a max of 100mA.
As far as the device in the video though, it's possible that it was using that distance of isolation just because it's easier to assemble or something. Though that would require the engineers to actually talk to the lowley operators for DFM, and that is a stretch.
Ya need to have a big motor and weight in there, so when the counter reaches 0, it vibrates like mad, dancing across the floor, then stops, and a little voice says "bang."
I swear this looks like the training drone that Luke skywalker and obi wan kenobi use in Star Wars Episode 4: A New Hope
Please do! Replace those sensors with red LEDs that light up when "armed". It would be nice if it had an audible hum too.
And put it just behind your mailbox outside...
Also some beeps increasing in tempo als it counts down the last 30s.
Would be cool to turn it into a big thermal detonator from SW. You trip a sensor when you walk by it and it starts to glow red from the four pods, and makes the sound of a TD, and then starts counting down. Could scare someone new to his work area. LOL
Glitter bomb is for loosers lmao 🤣
Make the count down timer light up and start counting when touched or moved. Just think the fun you could have.
Yeeep!! As soon as the movement stops it can add back a suitable remaining time... Bonus for a eerily calm womans voice "Danger avoided... Enjoy your day!"
You will probably find the TO220 devices on the heatsink are the heater, for preventing icing in cold climates. Fuse is soldered in so people can't replace it with a wrong item reason is:. That opto isolated area is all about limited energy so there's not enough power there to generate a spark at the microphones in any possible conditions. The power will get across there via that fuse then there will be zeners to limit voltage and blow the fuse. There is also a mandated clearance distance around that intrinsically safe circuit, which is why the homebrew optocouplers exist.
"Banshee 343" - Is the name of this a video game reference? The Banshee is a vehicle in Halo, and 343 is "343 Guilty Spark" from Halo. Halo series is now looked after by 343 industries.
You have the explosion proof issue backwards (I have sold industrial electrical equipment for over 40 years and have sold thousands of EX rates pieces of equipment).. They are designed so that if there is a failure inside and ignites the gas inside the device the flames and or explosion is contained and wont ignite anything outside the device.. If there is a breather it will have a very fine metal wool inside to prevent flame propagation (If they made all their own components they could have hid the breather in the cable connector). The inside volume is usually very small to limit the volume of flammable gas.. Less gas, less internal pressure if there is a fire or explosion inside. The volume of this device is huge thus the extremely heavy walls.
Looks like it has been dropped at some point. The posts holding the internal PCBs had snapped off which is why there were so many crinkle washers loose inside. Along with a countdown timer you need to add some accessible wires that can be cut to stop the countdown (but which colour should be cut? red? blue? green?) and if the wrong one gets cut it lights a small pyro to scare the bejesus out of you.
Yes you HAVE to make that display into a countdown timer, complete with piezo speaker that makes the classic "pip - pip - pip" sound that all bombs make in the movies/TV shows like MacGyver :) Perhaps you could even get pretty cluey and when it reaches 2 minutes left, include a capacitor charging sound (i.e. detonation/firing circuits charging up!) Yes it does look like a WWII sea mine!
I love how excited he sounds through the whole video.
Hi Dave , The Key to EP is not to pressure seal completely, but let the hot gases cool as they leak out so they can not ignite the atmosphere outside.
You should totally make a countdown for that! Maybe also have it make whirl click and beep sounds as it counts down.
Someone has probably mentioned it already but on page 22 of the manual, the empty space, between the sensor houses, is described as "pump compartment".
Also, on page 46, an "H2S pump" is listed as a spare part.
There are some much less beautiful sensors equipped with IIoT, which also detect the ultrasonic sound of water pipes leaking. To increase the precision of the detection, they are used in large numbers in a mesh network.
A few years back I built clock which would read the correct time except that the seconds would count down.
I started making a case for it from PVC pipes but figured it little might cause some panic so I never finished it. But maybe sounds like a good project for your case.
That’s a great idea! So it’s nice and functional at the same time.
I have an empty high pressure gas cylinder that I really want to weld some fins on, paint it military green and half bury in the front garden. I'm just worried I might end up with the police or bomb squad knocking on my door!
That tiny board might be a hall sensor to allow external test activation with a magnet
That housing looks like steel casting, so more likely internal temperature sensor, used to both compensate for speed of sound, and also to activate heaters when the unit is in icing conditions, though the heaters look like an option not on this model.
@@SeanBZA Yes, I think it's a temp sensor for the optional internal heater, so it's measuring the case temperature.
If you think about it, in a weird way it actually is pretty cool and beautiful...all the machining, the paint job, etc
I can see this thing be a perfect empty shell for either a movie prop or a "defuse the bomb" kind of gimmick that can be used in airsoft games or an escape room. You could put some RGB LEDs in the transducers together with a speaker to signal the bomb has detonated and the "defusing" team has lost.
The IR can be used with a simple TV remote for code input to defuse it.
Or maybe something that releases a heavy spring with a weight.
The pcb for the countdouwn should also have a speaker that does ‘tick, tick…’, or possibly a loud relay.
Needs a motion sensor so it starts the countdown when you pick it up.
Then just leave it around the lab until someone picks it up for a closer look, “uh-oh, now you’re bu**ered!”.
Then some secret way of manipulating it so it stops. Perhaps a certain number of deceleration events by smacking it on the table in various orientations.
An accelerometer inside to make it act like a magic 8 ball. Turn it upside down to shut it off.
Why did you censor buttered?
@@elpechos it's probably buggered, which is a pretty foul word (buttraped, pretty much) in UK English.
@@DanBowkley Could be bunkered
Perfect sealing is not important. What is is preventing any flames or sparks from getting out. There is no gunk inside the cable because the cable is effectively acting like a spark/flame suppressor, wicking the heat out of whatever gasses may be attempting to make their way through long before they have a chance to ignite anything.
"Internal heating" - 160W power consumption
They play the same game with security cameras.
Yes please do the counter!! You could also add a little smoke machine so it starts to smoke when it gets to zero
Totally looks like something out of Tales from the Loop. I Want one.
Those types of DIY optocouplers are very common in Fender guitar amps. They call them "dead bugs" and are used for the tremolo effect. The bulb is hooked to a phase shift oscillator and the LDR is used to dampen the signal.
thank you! This is adorable, this thing has been assembled by hand by skillful workers.
I would retro-engeneer the counter and use it as a time display, add a MP3 player circuit in there and use it to listen to music in the bus :p
20 years ago our Cl2 plant was built new and the old Cl2 plant was decommissioned. Some years prior to that an operator was sadly killed in the old plant when he started a Hydrogen compressor and the local control panel exploded, H2 had crept from the compressor though the conduit into the cabinet and ignited when a start button was depressed. Thank God our cabinets are now pressurised with low pressure alarms on them.
QUALITY !! Investigate the component selection, solder quality, machining, materials, thermal management, and de-rated circuit biasing for a true appreciation of a very robust Design !
This totally needs some sort of IOT connection, perhaps to set the timer, to start the countdown and a webcam or lighting, all linked to the EEVblog website 🙂
It would be interesting to see if the cable bundle is stuffed with potting material at any point. On one hand, a flame could not readily propagate the length of the air passages from one side to the other; on the other hand, the blue sealant would be superfluous if gases are free to diffuse through the bundle.
You should paint the case yellow with black diagonal warning stripes around the midsection.
I'd be keen to see multiple videos related to the "build a counter circuit" idea. Reverse-engineering in one, block-diagram design of the replacement in another, then schematic design, followed by PCB design and then final finished project presentation to round out a cool 5! :)
This Is an incredible find. I have only seen one similar device. That was in the early eighties.
I had a neighbor who was a top notch nuclear physicist. He took me on a tour of Brookhaven lab ( and his experiments in the early 70's. This instrument is a result of the experimentation of that era.)
Thank you for showing the basic tech. You should look back to the origins.
I worked in the intelligence us Navy, in the 80's and this type of system was just being instrumented.
This is what you get when you tell an engineer their is no budget. Just beautiful.
At first glance I was reminded of the on board fire extinguisher pods on USARMY Sikorsky UH60 Blackhawk Helicopters. I was looking for the firing squib ports on that bit of kit there. Thanks Dave !
As far as the heater, look at the part you referred to as a heat sink. Loved the video
I work with designing LNG plants and have never seen a ultrasonic gas detector before. Super cool! If there is a good leak, the sound can be really loud and not just in the ultrasonic range. One thing I always found interesting is that pt100 elements is one of the best ways of detecting liquefied gas leaks :)
The engineering that went into that is crazy. Its such a complex function for such a simple looking device.
"Banshee 343" sounds like folks from Halo designed the thing
At first I had the same thought of being something used underwater...maybe sonar or underwater microphone for example. And you can go further than just a clock. You know you can!
It looks a bit like 343 Guilty Spark, can't be coincidence right?
It's surprising to me that there's so much empty space inside. I would have thought that having as little room for gases to accumulate would be a good thing.
It has to be spherical for maximum strength - which makes it hard to efficiently cram in circuit boards. You could have a stack of circular boards of varying diameters, but it's easier and cheaper to just make the case bigger and heavier.
And just like the Death Star, it has a convenient, tiny path of ingress through the cabling to all the sensitive bits inside.
I used to assemble troubleshoot and repair infrared light curtains ..which were safety devices used in machinery where limbs could get damaged ...and we got an order for an explosion proof light curtain once which we made with stainless steel .
The Opto Isolator is not an LED-LED but would be a 2 pin photo transistor, Probaly in a plastic tube under the heatshrink.
I think you need to put the timer onto this with your kids so they can take it to school for show and tell to show the other kids what they and dad made on the weekend.
mmm... a nice countdown timer, flashing leds in place of the sensors, and a bleeper starting at 1 minute - getting faster and faster as it gets closer to zero. All controled via the IR sensor on the display board
@9.25 i think leak internal is no issue as both parts are in the exd box. The glands to go in and out have epoxy harderner and only strands are allowed. Sometimes cables are allowe but the a minimal length is required of a certified cable. In the usa conduit is used with a kind of concrete filling in y shaped pieces. All is pretty hard to service, ask me why i know :-)
With those rotary sw. one can set up the Scale for the 4 to 20 mA courrent loop . ( Pv for 4mA , for low value , 20 for Hi Value for ex.) In case your SCADA system has AMS included , ( for ex like Emerson DeltaV can have ) you get a lot of info from , or you can remotely set up the mesuring ranges etc on a nice interface on your Professional Plus WorkStation
I want one of those. Have no clue what I would do with it, but I want one.
When working in maritime electronics we used to have to travel by air, the same applies to things like ships Gyro's, (and your tools), airlines don't like them at all!
I remember we used to test for intrinsically safe gear, you put it in a flammable atmosphere and try it!! We had to do it with radio's for the mines. (at Philips TDS).
Good video..
Add a counter.. But also add a vibration motor inside so it begins to rattle and shake.
I love seeing things like the numbers scribbled in sharpie on the female connectors coming from the potted area. It tells me that whoever manufactured that part of the unit wanted to keep track of which cables went where. The human touch that this adds to an otherwise decidedly industrial object tickles my brain in a fun way.
If the fuse is blown the whole thing gets replaced regardless of if you could make it work again. It's a saftey/insurance thing.
I would have thought it'd check the change in the speed of sound not the sound of escaping gas with those ultrasonic sensors, ergo the range specified being very specific.
Ex d "electronics" is neither really explosion proof nor is it gas-tight. It is designed so that an explosion/flame on the inside cannot penetrate to the outside of the case and cause an explosion there. So basically the nearly Standard electronics is packed inside a huge hunk of metal wich can withstand the blast of an explosion of the inside volume and the metal case has very small distance (and elongated) gaps through which a flame from the explosion cannot escape
16:19 Makes perfect sense to me though. Full of explosive gas and something move the shell but will make the fuse move a micrometer and produce a micro sized spark that is more than enough to ignite the gas. They do everything they can to prevent any spark to be created.
555 timer opportunity? Perhaps have several options for the display: time of day, temp of the case, count down timer. Count up timer. Maybe put a button instead of a sensor in one of the 4 ports.
Yes build the time board, plenty of room to put in a massive pouch cell and controller, using the IR receiver, along with a generic credit card transmitter, to do the count down. Use the one port to connect a piezo speaker to play the beeps, repurposing 2 of the connection wires for that, and the existing power connection for charging the pouch cell.
Also, make the countdown speed up if it's moved.
I was thinking a primary battery that lasted a decade. None of that rechargable rubbish.
@@EEVblog Big 10Ah pouch cell is cheaper, and will do that no problem. Charge not needed unless you are really wanting, just leave out the discharge protection, or find a micropower one that uses less than the DW01 used everywhere, and the pouch will hold charge for the decade.
Make a widow for a solar panel to power battery then to the display?
Thermometer with temp display?
Time capsule with count down till open display? Or days since opened display?
There appears to be some missing components. The Self-Test documentation mentions a self-contained direct drive pump to provide compressed air that is forced through nozzles to create test sound. Where is that pump and plumbing?? A pump would also explain the seemingly excessive internal volume.
5:26 that kind of looks like a burst disc, which is a telltale for pressure waves in air. they can be calibrated to burst at specific pressures to indicate how strong a blast is (in terms of the pressure wave). i've never seen a burst disc hidden behind a sealed panel though. that panel over it almost looks like a GPS antenna, but its facing the wrong way lol
Banshee 343? Is that a Halo reference? 343 Industries is apparently named after the character 343 Guilty Spark, which would be fitting for an explosion detector, and it even looks a bit like him.... the font even looks like the 343 Industries logo
The relays aren't for heaters or other internal parts, they are exposed on the interface panel as external NO and NC signal contacts.
Also, the shape and size of that pressure vessel is too damned similar to an implosion-type nuclear or thermonuclear bomb, except for the internal.
Funny how a doomsday preventing device looks so much like a Futurama doomsday device.
Yes!
Do a countdown circuit for the display. Paired with a "bip, bip" 1-second beep going to a sound transducer.
I didn't know I needed to see inside this thing until just now.
Would be very cool to deconstruct and rebuild something like this.
This , ( color ) indicates a Rosemount product . There , where the M1 stands, a HART comm ,little transceiver modul is missing ( Bell 202 modulation superimposed over the courent loop ) And yes , those products are expensive and very Reliable
i used to have to do temporary installations (days, to weeks, or months) of "explosion proof" CRT monitor housings. They were ridiculously heavy and cumbersome, and required their own compressed air supply to keep the housing at a higher pressure than the outside environment. Eventually we moved away from CRTs and the need for air, but they retained their weight and overall awkwardness. Better to have these working than to have an oil rig blow up though...
Hazy memory but I did a bit of Exd and Exe design for UK offshore back in the day (80's/90's), so this unit is Exd meaning it's explosion proof, i.e. Any major problems on the inside won't propogate outside.
The cable glanding and the ultrasonic sensors, i.e. Anything that connects from the internal space to the external world has to be Exd rated. There were some types of cable entries/glands that had to be packed with an epoxy type stuff.
It's all about flame paths.
If I remember correctly, you had to declare and submit a BOM and layout drg for the internals in order to comply with the Baseefa/ATEX Exd rating before use.
Once done, you couldn't drill any holes or strictly speaking change any internal parts.
Exe (I.S. intrinsically safe) was different, that was all about limiting voltages and currents via certified interface modules including zener barriers, galvanic isolators etc. I did more design on the I.S. side. I remember designing and getting approval for a large Exe Lcd display and during the cert process being limited to the amount of total capacitance on my Pcb, the distance between components etc etc.
With Exd, you are given a lot more lateral.
Dave's unit it would have been one expensive puppy back in the day........!
Ian
I assume BOM means Bill Of Materials. Something you don't want to be talking about in an airport or anywhere else near someone in security!
I suspect the led panel which you said had IR interface also, the chips on that board would be shift registers based on the number of cores in the ribbon cable attached to it..
At first I thought it was an airspace gyroscope. Anyway, I love expensive machinery teardowns, especially mil-spec items. Medical equipment is also high quality, way above consumer grade
You can use this sensors as a movement sensors, that will activate the countdown counter and maybe put a loudspeaker inside that will play something like "self destruction system engaged"
The fuse has to be soldered in because in case of a short circuit, you don't want someone to be able to replace the fuse and create a spark that could lead to an explosion!
Maybe the to220 are used as heaters
It's also ATEX certified: ATmosphere EXplosif. Some sewage pumps are also ATEX certified due to their working environment.
That thing was brand new. They don't look like that after even several months in tropical or marine environments.
Definitely want to see the countdown timer. You could add some red/green LED's where the sensors are for effect. I also like your idea of an IR interface to control it. You could get a generic TV remote to save some build time.
Each of the sensor housings has a cast-in orifice for actual pressurized gas to go through. I'm guessing they just did away with the extra pump and other items and just put the dummy plugs in place of it.
Those HDSP-U113 seven segments are really nice. This would make a great cooking timer for the kitchen.
At the prices mentioned here, this thing might be a good option for a highly custom PC case.
That would make an excellent egg cooker! Would fit perfectly on a kitchen table, in combination with the display counting down and a noisy speaker once the eggs are done.
That was an awesome tear down! And that would be so cool to have like an infrared sensor or remote controlled reset with a countdown. I'd love to see a project where you did that and just have it sitting on your shelf with it counting down LOL
The soldered fuse is no problem.
The whole electronics are over engineered.
If that fuse fails either the device is in the middle of a fire, over volted, or something seriously failed wich calls for an autopsy. In all cases there is no need for fuse replacement.
My question would rather be - does it still work?
Some of those devices are replaced on a schedule regardless of they work or not to be sure that they aren't failing due to age. And rubber seals ages as well.
Couldn't find the price for this model new but I did find one used/weathered on eBay that sold for around $270 USD. A similar looking device new from a different manufacturer is asking $20,000+ USD which sounds about right. Apparently they never have to be recalibrated for the life of the unit.
Yeah, I work in the water/wastewater industry and that price sounds about right for this kind of gear.
Funny that. Looks like a Mk. 5 Romulan photonic mine. Strange though I’ve never seen one uncloaked. Thanks for the unboxing vid!
The metal bowl at the bottom of the device is to collect all screws during teardown.
Yap, would make a neat clock! I guess you can rotate the display board inside 180 degrees, so you can read it in sensors up position. Thanks for your videos!
It seems that the silver conical cap is where you mount it to a pole.