Ultrasonic gas meter teardown

[@voidstar99]

Around 21:29 - essentially the same voltage measurement can be used to calculate the discharge rate. Since piezo's capacitance will strongly depend on pressure, wouldn't it actually be more likely that those pulses would be used to detect the gas pressure (and incidentally test the transducer as well)?

[@RODALCO2007]

Interesting, Thanks for doing the autopsy. Great test set up with the fan. Large battery I wonder how intrinsic safe this set up is. No doubt it is safe, as the gas authorities use these meters. That wire on that coil is very thick, must draw a bit of current.

[@davet11]

Fascinating - thanks Mike. Wow, they go to all that trouble to get a low voltage solenoid but have 50-80V transducer spikes within millimeters of the gas flow. Must be easy to confuse using an external ultrasound source. Great teardown - thanks.

[@cjmillsnun]

Spot on with your guess of how it works. As regards the lack of pressure sensor, there is a mechanical regulator attached to the inlet (a mushroom shaped thing on the top of the meter at the end of the flexi pipe when installed), that IIRC is set to 21mbar and has a tolerance of +/- 1mbar

[@electronalchemy7513]

Well this sure beats endless tennis on the telly. *Presses pause to go and make a cuppa* Proper Sunday night entertainment!

[@ThatLinuxGamer]

Fascinating piece of technology. It's amazing the lengths big business will go to to prevent someone getting their stuff for free. Not that that's a bad thing, I'm sure the research and development involved in making products like this helps further our knowledge of science and technology, I just think it's interesting to think about.

[@ihardon22]

One argument for separate meter and card units is that they could keep the meter in place (since it'll be a pain to change), regardless of the type of customer, and simply bolt on or remove the card unit as the customer moves on or off of prepay metering. I guess it could also open up alternative means of prepayment, or the ability to support different prepay card systems. That way you don't have to maintain separate meter stocks or pay for card functionality on every meter, regardless of need

[@usagold8]

It would be interesting to have seen the Infrared communication between the smartcard unit and the meter, especially to see if they used some form of polling or obfuscation to prevent tampering.

[@MrOrrery]

Many years ago I was involved in the in-house testing of an ultrasonic domestic gas meter, very similar to the one shown here. The IR port is a standard feature, with a publicly published protocol used by all meter manufacturers, for both gas and electric. The protocol starts at a low baud rate to establish connection, then switches to a higher baud rate for the functions, including setting the charge rate and controlling the valve. The switch from low to high baud rate includes a password. This is the security mechanism, and it would not be easy to crack. While testing these meters we discovered that if the transmission during the low baud phase was allowed to overrun, e.g. by sending a continuous stream of garbage characters, the internal receive buffer would overflow and corrupt some RAM. The 'garbage characters' could be any form of IR transmission, such as from a TV remote. This corruption would be detected when the meter did a status check, which it did every six hours. The meter then corrected the RAM by reloading it with the 'last known good' values, which could be upto six hours old. I pointed out that a devious person could get 6 hours of free gas by using a TV remote. Do this every 6 hours and he would have free gas all the time. The company then fixed the software bug in all new meters, but nothing could be done about the 20,000 meters already installed !. So somewhere in the UK there are 20,000 users possibly getting free gas just by using their TV remote. I wish I was one .

[@electronicsNmore]

Excellent Video!

[@arongooch]

As if you'de get thumbs down for a video like this? What more do people want. I dont get it. Love the teardowns.

[@0xbenedikt]

Would it be possible to use a strong IR source from the side to possibly saturate the IR sensor inside the actual gas meter before the card runs out of credit to prevent the transmit of the turn-off sequence?

[@mrsipo1975]

What a ride.Thank you.

[@mattbeddw]

eres a regulator that sits before this that keeps the pressure constant (21mbar) regardless of what the supply pressure is (usually nearer 25mbar) so there isnt a need for a pressure sensor, purely volumetric. it used to be quite a common way of getting more gas for your money by fiddling the regulators to up the pressure but they have lead seals on them now.

[@cjmillsnun]

Matt Beddow depends whether it's an LP or MP service. MP services can be up to 2 bar, and LP up to 75mbar. (although you would have to be near the district governor and for it to be at winter settings to see those kind of pressures). The more modern regs have plastic seals, but do regulate to 21mbar as you say. That said, ultrasonics aren't as dependent on pressure as the old diaphragm meters for an accurate reading, therefore even if you could tweak the pressures slightly it would make little difference to the accuracy. Both the E6 and the U6 are designed to flow at a rate of no more than 6m3/hour.

[@nRADRUS]

Matt Beddow , relative pressure is fixed, but what about absolute pressure VS speed of sound?

[@mattbeddw]

The whole gas network is billed on relative pressure not absolute. When your looking at 80 bar in the High pressure mains a few mbar shift is negligible. When you get down to Low pressure service for your house it may be noticeable but the accuracy of domestic meters isnt fantastic anyway. thats why they measure down to 1000ths of a m3 but you are only billed for whole cubic meters/feet. Long term averaging then takes care of the short term fluctuations in gas pressures.

[@Graham_Langley]

nRADRUS The variation with temperature is far greater.

[@cjmillsnun]

Matt Beddow Just seen you work for National. I work for one of the other DNs.

[@Tadesan]

27:30 That shape is not to reduce turbulence. Although it probably does do that... I'd bet a huge sum of money that is an acoustic horn. it's job is to transform the acoustic impedance of that channel to the impedance of the free space inside that box to reduce reflections. If those tubes just terminated there would be extreme standing waves generated that could interfere with the measurement.

[@MM0SDK]

Is that a desolder pump with a heated tip of some sort? Not seen one before.

[@DrTune]

+Mark Bartlett They usually have the heated tip and vacuum pump and usually a foot (or finger) operated switch. They're fantastic for desoldering.

[@nexaentertainment2764]

That folding on the can, I think it's a fairly similar method they use on Soda Cans. It's a fairly easy and cheap and reasonably strong way to hermetically seal something. I believe it's type of double seal, but I could be wrong.

[@TheEPROM9]

One also wonders how easy it would be to block the IR coms by slipping something opaque between the meter and card unit so they can not communicate and then the card unit can't tell the meter to cut off the gas when the money runs out.

[@Coolkeys2009]

***** If gas valve is in the metering section it could be programmed to cut of the gas after so many units are supplied unless told otherwise, and also cut off the gas if there are communication problems, or just log or all the evidence and write it to the smart card for evidence for use in the up coming court case :-)

[@frtard]

***** Would liked to have seen some waveforms and a dump off the eeprom. It's amazing how many devices you think should be secure actually use some really poor crypto.

[@TheEPROM9]

That is why it would have been fun to experiment with it to see if the thing is secure.

[@SCAJolly]

03:57 "CALL HELP AAAEeegheg x_x"

[@nRADRUS]

jolly , new model will send radio message into service :) SOS :)

[@J2897Tutorials]

+nRADRUS It can be adjusted remotely too. So they can make it tell you that you've used X amount of gas when you've really just used Y.

[@lehnhardtdevonek.8479]

mmmmmmmmmmmmmmr Bean!!!

[@J2897Tutorials]

May Devone That's a different character. Search my name. It's his best character yet. :)

[@lehnhardtdevonek.8479]

ok

[@Landrew0]

Truly brilliant analysis.

[@Novalight2550]

Now lets decode the infrared communications and/or fuzz it.

[@wakjah1]

The narrowness of the flow rate measurement tube is probably so that the waves remain planar up to a fairly high frequency and they don't have to worry about positioning the transducer over an antinode of a standing wave (at least in one of the dimensions)

[@HelplessFear]

Large amount of copper on the coil. Possibly for running at a lower voltage? It was a big coil, also could be for spark isolation? What kind of desoldering gun were you using in this video?

[@Arnthorg]

I wonder if you can have a system listening for the clicks the transducers make and time opening and closing of a solenoid to get unmetered gas.

Arnþór Gíslason By seeing that it does not speed up measurements when flow is huge, it looks like it can be easily made. For better effect you should store this "stolen" gas in some tank so that you can use it without pause every 2 seconds.

[@pickholder6189]

Whats the nice desolder tool you used Mike?

[@Kezat]

Could the low voltage solenoid be a safety feature? Kind of like a intrinsically safe device? Lower voltage for a lower chance of a spark?

[@Redat23]

Curious question that sprung to mind, what if you were to construct a lead cage around a smart meter ?

[@TheMrTape]

I think they can measure pressure from the sound volume received.

[@thermaldog]

Any idea how I can find out the speed of the pulsed transmissions from smart meters?

[@MrLodonlondon]

Do old pre pay card gas meters recharge themselves. I had same card meter over 15 years? Battery still good!

[@kristhetrader5029]

Fascinating Mike, keep them up mate!

[@pinnyb3213]

Just had my meter attended to. The meter was taken off with and the guy was hammering something off with a screwdriver in the inlet end of the meter. Any ideas on what was done

[@Spoif]

@mikeselectricstuff Isn't there a regulator before the meter, so the gas pressure would be known?

[@douro20]

It's possible that those ultrasonic sensors are made by Bosch; they are very similar to the sensors they make for the ParkPilot parking assistance system.

[@SrChasJC]

Nice teardown, thanks!

[@BritishEngineer]

I study hydraulic civil engineering and sewer sanitation. They use ultrasonic flow meter and a flume with known dimensions to use as referencial variables, calculated the quantities.

[@Minifig666]

Very cool. Never realised you could use ultrasonics in this way! I was a little puzzled as to why the valve is on the supply side. Maybe I'm having a brain fart, but wouldn't it be easier to switch so the stopper is pulled to the low pressure side?

[@deangreenhough3479]

The pressure is already reduced before it enters the meter. The meter does not regulate the pressure. A gas regulator is always before the meter. Therefore, it makes no difference on which side it is on. I was a gas engineer for 15 years and fascinated to see Inside.

[@julianhowarth1075]

Is this the same as a modern day smart meter ? ....

[@chrisb4009]

The amount of Will will be due to the fact it has to be intrinsically safe to be operated on a zone 0 environment. The coil would have to be ATEX certified Exia for the application.

[@random5147]

How do you reset a mechanical pay monthly gas meter back to all zero's and how do you replace the battery on a gas top up meter ?

[@1701spacecadet]

Can the pulses be reprogrammed to set the interval at a fixed interval? Then use a matched timed valve so the public can limit their contribution to the obscene profits the fat cats 'earn'?

[@joosera]

Maybe the reason why the solenoid is so huge is so they can use low voltage for explosion safety? The solenoid is inside the gas flow, wouldn't it be easier to ignite it with higher voltage?

[@alynicholls3230]

hi mike, a couple of those spools of copper wire would be great for when i wind metal detector coils.

[@Xenro66]

Anti-tamper, huh? What if you just apply some glue to it and pull it out? It wouldn't damage the little cover thing.

[@colinstamp9053]

When trying to measure current consumption on something like this, a nice method is to use a V to F converter (e.g. LM331) and a frequency counter. Then you get a huge dynamic range and inherent integration.

[@nRADRUS]

Colin Stamp , analog integration is bad cuz it intergate bias ;)

[@douro20]

It's not surprising that is sealed like that; it probably has more to do with compability with flammable gases than with anti-tamper.

[@cjmillsnun]

douro20 bingo. It has to be intrinsically safe.

[@MustafaTULU32]

Please tell me which device you used at 11:31

[@pyrobeav2005]

It is a desoldering gun, a soldering iron with a vacuum to remove the melted solder. Not sure exactly what model Mike has. kzbin.info/www/bejne/hJmsq3ere8-lic0

[@theelmonk]

Won't the absolute speed of sound in the gas give the pressure ? So relative forward / backwards speed gives flow rate, but average between the two directions gives some function of pressure and density.

[@Graham_Langley]

theelmonk Unfortunately the variation with temperature is far greater.

[@woolseyjd]

How much do these sell for? And how much would you estimate the parts and/or manufacturing cost of one of these would be?

[@chrisb4009]

The governor in the on the gas meter regulates inlet pressure to a nominal 21 mbar. I assume they rely on the Gaussian distribution in this and win some and loose others.

[@afroninjadeluxe]

to do this kind of ultrasonic sound measurement is the speed of a microcontroller like atmega8 enough (16mhz)? There cant be very much difference between the travel time for the sound in moving liquid vs. static liquid.

[@schnozberry2]

is the 'b' for BTUs?

[@fpskywalker]

So the solenoid is to shutdown the gas service remotely if you don’t pay?

[@TLCLaundryCentre]

until it has communication with the grid. If u can break or disturb the communication with the central system, its not possible anymore. Even if its a prepayment nmeter , the meter cannot get the the new unit prices without communication in case of price increase. Its enough to shield the electric meter to destroy communication betwen gas and electric meter or use Flipper zero to find the frquency.

[@Spongman]

probably a larger coil to reduce the voltage. high voltage discharges & gas don't mix.

[@l3m0ngr455]

I like your video's. They are neat and educative.

[@Rouverius]

I wonder if the choice of such a beefy solenoid was to reduce the risk of sparks.

[@Tadesan]

what is that in micro kwh?

[@katelikesrectangles]

Could you move the solenoid with a large external magnet?

[@sivalley]

katelikesrectangles Not likely since it is in a 'seamless' metal can and therefore intrinsically magnetically shielded

[@superdau]

sivalley A metal can does in now way mean it's magnetically shielded.

[@jibcot8541]

Interesting and detailed, my one of these with an install date of 2016 battery ran out in 2021, so the 10-20 year battery prediction was a bit too generous but at least it didn't close the value so I have unlimited estimated gas usage for the mean time.

[@cjmillsnun]

I'm surprised you managed to get one of them.

[@smartchocolate6503]

Wow I'm surprised how easily the cover came off. Does all the cover off as easily as the model in the video. I have similar E6 gas meter

[@fibrodad1354]

I have pre-pay and own my own home, it was here when i moved in and i love it. no bills every three months, and the tariff is the SAME as direct debit duel fuel. I work for a fuel supplier and sell supply and people have these for all different reasons... good vid again but i had to clear up your assumptions.

[@Redat23]

+JRushPixel You work for a fuel supplier says it all. Perhaps you can clear up my assumptions by answering this.. are you people paid to go about marketing these new world order meters, or does it come with the territory ?

[@TimmyToil]

I have a meter just like this one, it seems to have gone faulty. When the gas supply is switched off at the main valve the reading is still increasing, i have performed a gas test and there are no leaks in the system. What could cause this fault condition Mike? Any help greatly appreciated!

[@JimGriffOne]

When you run out of gas credit and the meter is switched off, it asks you to "Hold A for gas" for 10 seconds. This activates a solenoid 10 seconds later, which is probably done after the capacitor has charged up in order to drive it with enough current.

[@alexsimpsn]

***** I suspect that the 10 second delay is also a slight safety feature, give people the chance to realise they're about to turn the gas back on and reduce the change of them blowing their kitchen up

[@pyrofer]

Has anybody done any research into the IR protocol? I have one of these and would like to monitor my usage and graph it so I can see how my heating is performing. It's easy with my electric as I just watch for a black bar on a spinning disc, but this is crazy. A webcam watching the LCD seems overkill so I wondered about an IR transceiver to get the readings from it.

[@electronalchemy7513]

I guess the solenoid turns it off when you run out of credit. Which makes it doubly surprising that it doesn't check the solenoid position on booting. Maybe 'b' = BTU?

[@cjmillsnun]

Electron Alchemy nope, we use megajules/m3 in the UK, (the standard being 37.5 - 43). It was faulty, hence the not pulsing the valve.

[@ChumpusRex]

Electron Alchemy I think the "b" is an indicator of a battery fault, and that the meter needs to be taken out of service for refurbishment.

[@arthurvin2937]

Imagine future where you need to stick your credit card into the meter to get breathable air. Quite realistic scenario let's after the nuke war.

[@Itisinthehand]

10 Dislikes: who are these people? Learnt loads here thank you . Very interesting.

[@J2897Tutorials]

British Gas bullshit about your meter readings too. If you pay quarterly and constantly stay in credit, watch out! They will fiddle your original meter reading and try to claim that you've actually always been in debt. So keep proof of your original meter readings (video your meter) and record all of your phone calls with them; otherwise you may soon be forced to have one of those expensive pre-payment things fitted. They screwed me over big time! I had around £400 in my savings account. They demanded the lot or else the door gets kicked in! I'm still on pre-payment meters.

[@devilmastah]

I wonder if you could trip this meter up by putting a big pizo on it sending random pulses

[@peterg.8245]

Auto ignition temperature of natural gas is just above 1000F so in an intrinsically safe battery operated system you never want to reach anywhere near especially with impurities like hydrogen. So I think in complete failure with the battery shorted across the solenoid it can dissipate the heat hence the thermal mass.

[@MarkTillotson]

Or its because more copper = less energy per actuation. More amp-turns means more resistance unless you use thicker wire, more turns and thicker wire = more copper. The total volts-amps can be held constant and the amp-turns increased without limit (until inductive effects matter).

[@MrDubje]

My parents' home is fitted with one very similar to this. Also Landis&Gyr and has the A/B buttons but no card reader. I guess it's not that common in the Netherlands, never heard of a pre-pay gas meter... It's connected with the energy meter (some flavour of an ISKRA Emeco) via a two wire M-bus en.wikipedia.org/wiki/Meter-Bus Since the energy meter is connected to a cellular network via GSM/GPRS it's possible for the energy company to shut off the gas remotely, but it also has a mode in which it's possible for the consumer to turn the gas on again by themselves.

[@UberAlphaSirus]

So you didn't come across any tamper switches? The tamper plugs should pop of quit nicely with a dab of hot glue and firm tug. We have the newer version you inset a picture of. 26pence per day standing charge and 4.73pence per cubic arbitrary unit as it doesn't say. We spend more on the privilege of having the thing than we pay for the actual dinosaur farts! On average.

[@thedjnk]

+Sirus No obvious tamper switches but as he said when he fiddled with the ultrasonic sensors, nothing was displayed - that doesn't mean nothing was logged however.

[@HDXFH]

a siemens Board!!!@19;58 looks like This is a Siemens Landis & Gyr Quality Unit!!!! their Electricity meters were!!

[@proluxelectronics7419]

All that security and all you need to do is shove a pencil down the inlet pipe and jam the valve open, Pipe back on, FREE GAS!! until meter man takes a reading of course (not very often with prepay). Big Thumb Up.

[@itzme883]

wouldn't a pencil burn? lol

[@Phen0mable]

you better tell us how to get gas for free or how to change tariff to absolute minimum

[@itzme883]

Phen0mable swap your meter

[@mercuryin1]

​@@itzme883 if you swap the meter for one from ebay for example they can know about it ? I mean any security tamper?

[@bgdwiepp]

By His Noodly Appendage! That solenoid is basically just a spool of enameled copper wire! I guess if you were to buy that just as a spool from farnell or RS you're looking at $20 USD! On a pre-paid unit, as far as circumvention goes I'd try to bypass/manipulate the credit mechanism - it's much more plausible to say " i lost my card" then "oops my meter seems to have exploded"

[@DOYLETWAT]

Just smash in the valve on the meter outlet for free gas

[@pinnyb3213]

Where is the valve

[@mercuryin1]

how can do that mate ? Thanks

[@arcadeuk]

Of course the Metcal is man enough :)

[@bretty453]

So is there anyway to "jam" it with loud ultrasonic "noise" from outside the enclosure? Asking for a friend 😂

[@markbell9742]

Who else do you know that does an electronic teardown with a side-grinder? Cheers, Mark

[@kainhall]

do a mechanical one next!

[@cjmillsnun]

***** Not much in them. Just a couple of diaphragms and a mechanical counter.

[@Lion_McLionhead]

If only cars had ultrasonic fuel gauges.

[@kainhall]

heroineworshipper it would only tell you flow rate..... which is done by knowing fuel PSI and injector fire time and hole size. as far as full tank or not..... the current systems work damn well.... and i think it would be able to measure it.... probably with more error than float basied systems....but you are taking more electronics out of a tank filled with explosive vapor sooooo lol.

[@compu85]

heroineworshipper My freind's RV has an ultrasonic fuel gauge.

[@kainhall]

more wire = less voltage needed = less battery usage. unless you want to change the battery every 2 months.... you need that extra wire

[@aptsys]

***** This doesn't really help the battery usage. The energy required to move the solenoid will still be the same no matter how many windings you have.

[@superdau]

***** Physics isn't really your forte, is it? There's a reason you don't run your house on 12V, why 230V is more efficient than 110V and power lines run at a few hundred kV.

[@kainhall]

superdau if you need say... 50 Tesla, or guass.... not sure what magnetism is measured in... to move that noid.... you could do it at 12 volts with less winding, or 8 volts with more winding. if you ran them both at 12 volts, the one with more windings would have a stronger field. would you need more amps? from what i understand.... only the extra bit needed because of the extra resistance in the wire. so less volts and the same amps..... isnt that less energy? ohms law?

[@superdau]

***** Looks like you're switching voltage and current. The magnetic field is linearily dependent on the current and the number of windings. So you can double the number of windings and get the same magnetic field with half the current. As it happens, by doubling the windings you also doubled the resistance (as long as you use exactly the same wire). Ohm's law tells you with the same voltage you now get half the current, which is exactly what we wanted. So if we can get the same magnetic field with half the current just by making more windings, why don't we do it? Almost sounds like free energy doesn't it? First the practical limitations: you have to use the same wire, which means your coil is now double the size. Then the above is only valid for an ideal coil. You have parasitic capacitance (the higher the more windings you have), the field does not scale with the number of windings in reality. But more importantly the inductance of a coil changes with the square of the number of windings! So doubling them yields four times the inductance. What is inductance? In simple terms "how much the coil fights change in current". So to even get half the current as before, you know have to "push" harder, or in technical terms aplly a higher voltage. So what did you gain? Nothing... And you could spare yourself all that explanation, if you just apply some basic physics knowledge. To move a mass (the plunger) around and exert a certain force, you need a certain amount of energy. You can tune the efficiency maybe (most likely the reason why the coil looks like it does), but you can't break the laws of physics.

[@uzaiyaro]

Huh, the double seam shown at 13:25 reminds me of how a coke can is put together.

[@javierteo5807]

Take it out and put your own private meter in :-)

[@Graham_Langley]

A bit late, and apologies if anyone else has posted it, but here's a link to the makers of shut-off valves including ones used by L&G: www.nsfcontrols.co.uk/our-products/shut-off-valve/

[@TKomoski]

Mike could I send you my girlfriend for a teardown, because for the life of me I can't figure her out. With your expertise maybe we can get to the bottom of her. And if you would be so kind as to send a couple of things back from the teardown, that would be great because I need them. Just thought I would ask, Cheers.

[@bobbailey8246]

T Komoski If I may be so bold to suggest....a teardown of 'er indoors wouldn't do any good, women are analogue, men are digital. If they had a reset button (that worked), life would be so much simpler :-)

[@IamMinnie90]

You will never figure women out. We can't even figure ourselves out.

[@DUB-sential]

I'm 1/3 through.. I can't help but wonder if a stand alone test of mechanical vs electronic metering test of gas through the two would yield the same results for usage, don't get me wrong I'm no expert just intrigued if all this extra electronics is ripping people of that's all and obviously to test at different usages would be ideal, to get a jist if the new tech is fair to the consumer. Even though clearly usage is more or less based on the little man trying to keep warm vs industry getting cheaper prices for higher usage. In the end old people sitting cold isn't a good feeling for me.. Nor is anyone when so much rubbish is manufactured for it to go in the bin it's senseless. Maybe I'm just getting old

[@HDXFH]

interesting kinda like Electromagnetic water meters, these will get smarter!!, then roll them out lol!!

[@nRADRUS]

Designer corrupted by copper corporation ))

[@StefanHacker]

nRADRUS Talking out of my ass here but maybe by using thick copper wire they could reduce the voltage and hence simplify their regulatory approval process because of lower risk of sparks? No idea if that's a thing.

[@nRADRUS]

Stefan Hacker big inductance increase risk of sparks when switch off. thick copper can absorb high-frequency disturbances by foucault currents, but it will be cost-non-optimal solution again.

[@exproducermichael]

Hey, I really love your videos, but lately it just seems like you have been doing mostly teardowns. Not that it isnt cool watching you tear things apart, but I would really love to see you build some stuff. It doesn't have be terribly complicated either.