Cracking Gas metering

Hi folks,

I'm running openenergymonitors in 12 houses now (for electricity use, heat and humidity), but really want to be able to monitor gas. There is a fair few meters out there and I know that there are many people on these forums who are successfully metering their gas. I'm trying to compile a list of meters, what is needed to monitor them in terms of hardware and code, so I can usefully add to the gas metering page.

If anyone has anything to add on any of the following (even if it's what doesn't work), that would be really helpful. I'm a real newbie to arduino and electronics in general but have written a good deal of technical and end-user documentation and I can follow instructions. Ideally the low-power version of emontx makes a good basis as some meters are located outside the house. So here goes.

There is very useful info from National Grid on identifying your gas meter here, but I found images too small, here are ones I've taken recently (click to enlarge).

Eurometer E6

From my understanding the same as the George Wilson E6. Uses ultrasound pulses to measure flow.

I'd assumed we would monitor this with a pulse meter (from LEDs on front), but hear from Marsflyer via Trystan that this won't work. Any thoughts, assuming digital display models don't have a moving magnet we can monitor?





Krom Schroder G4 (BK-G4)

Krom Schroder BK-G4A measurement via diaphragm. National Grid claims not to have purchased these since 2002, but they seem very common (at least in Manchester).









Actaris / Schlumberger G4


Actaris Pulse meterWish there were more of these. Anyone already running a low power version of emontx pulse?










Pre-metric - U6 - the standard

Pre-metric U6We got lots of these, from George Wilson and other companies as well, but apparently all work in the same way.









U6 with some kind of monitor?

This one is puzzling, it appears to have a british gas branded wireless monitor on it, the householder doesn't know what it is or when it was installed. Any thoughts are where it might be sending?








I've got myself some of the Diodes AH180N hall monitors as recommended on the gas page, I also got hold of some of the A3214EUA-T sensors that Nathan Chantrell has successully used with the Tinytx for gas monitoring but I don't have any of those boards (and a bit scared of pcb ordering if I'm honest).

Sorry for huge post. Any thoughts or pointers?


elyobelyob's picture

Re: Cracking Gas metering

I have the final monitor in your list, and as I run a current cost monitor I used one of their development boards. It has an output to measure the pulses. Am pretty sure a TinyTX would be fine to use. I knew nothing about ordering pcb ordering wither, but have since ordered two lots of TinyTX2's .. I do have quite a few here, so if you want some, contact me with a direct message.

I will likely be moving to TinyTX3 at some point.


ricadelic's picture

Re: Cracking Gas metering

The Krom Schroder G4 (BK-G4) gass meter can be fitted with a reed switch available at I have ordered one and i'll let you know how i get on :-)


StuntMonkeh's picture

Re: Cracking Gas metering

Rick,  I have the same setup.

Seems to be working okay, its been running since mid Jan running on a 9v battery sending the number of pulses read in the last interval every 15mins.

robw's picture

Re: Cracking Gas metering

I'm also looking to do this but I'm having problems with the code. Anyone willing to share their own code I would be very grateful.


tomkerswill's picture

Re: Cracking Gas metering

I've got the BK-G4 too (also in Manchester, UK). Looks like the install date was 2004. @ricadelic and @StuntMonkeh - The reed switch setup sounds good. Are there more details on how to get this working with Open Energy Monitor? Would love to have a go. Thanks!


boelle's picture

Re: Cracking Gas metering

not that i have any of the meters...


but from the looks of it i think the Eurometer E6 uses IR coms, hence the 2 "leds" 

gazza_d's picture

Re: Cracking Gas metering

I have an actaris, which has an RJ socket on the underside and I gather I can just plug in a pulse counter.

However, it is in an outside cabinet, and we occasionally get unplanned meter reads, and I have a concern that if a meter reader sees a cable hooked into the meter they will hit the panic button and we will get hammered for unauthorised equipment connection. There is no space in front of the meter for a non-invasive counter.

what's people's view on this?

Also what sort of range can the pulses be counted? as my current emontx is about 10 m away.

My emonbase (Nanode) is closer, and I have a Raspberry Pi very close too if I could leverage either of them to count and report the pulses


boelle's picture

Re: Cracking Gas metering

10 meters is no problem.... 


but its is the range between emontx and emonbase that counts...  so if its in fact only 5 meters absolute no problem


about the meter... anything you have access to without breaking a seal is OK... if they dont want you to access that port they should just install an empty rj45 with a seal so you would have to break it to get access


if you are inside the EU there are actually rules for that they have to allow you to connect a device to the meter, provided that this devices does not interfere with the meter itself...... this is for those remote read meters many companies use these days... it counts for all meters installed after 2008 if not remembering wrong



Jérôme's picture

Re: Cracking Gas metering

The source for this EU rule would be interesting.

There are a few threads about gas and pulse counting. I've tried things myself, and I'm not done with it. I've been discussing this on the forum.

It would be worth centralizing the information.

For instance, create a page on the website, first gather the related thread links, then try to synthesize.

The synthesis is not easy as there are many different situations. For the same reason, it is not easy to create a sketch that suits all needs.

ukmoose's picture

Re: Cracking Gas metering

Like this page? 

boelle's picture

Re: Cracking Gas metering

source in danish:


a buttom:


"bekendtgørelsen indeholder bestemmelser, der gennemfører dele af Europa-Parlamentets og Rådets direktiv 2009/72/EF af 13. juli 2009 om fælles regler for det indre marked for elektricitet og om ophævelse af direktiv 2003/54/EF, EU-Tidende 2009, nr. L 211, side 55, og dele af Europa-Parlamentets og Rådets direktiv 2012/27/EU af 25. oktober 2012 om energieffektivitet, om ophævelse af direktiv 2009/125/EF og 2010/30/EU samt om ophævelse af direktiv 2004/8/EF og 2006/32/EF, EU-Tidende 2012, nr. L 315, side 1. Bekendtgørelsen har som udkast været notificeret i overensstemmelse med Europa-Parlamentets og Rådets direktiv 98/34/EF (informationsproceduredirektivet), som ændret ved direktiv 98/48/EF"


top line says, roughly that the notice implements parts of EU directive 2009/72/EF dated 13. july 2009 concerning common rules for the inner market of electricity and suspension of eu directive 2003/54/EF........ 2012/27/EU dated 25 october 2012........ 2009/125/EF and 2010/30/EU........2004/8/EF and 2006/32/EF......


the notice also as draft been noticed to be in sompliance with eu directive  98/34/EF changed in directive 98/48/EF


you can substitute EF with EU in the directive numbers...


BUT note install date of your meter comes in to play... if meter is installed before your country implemented this it does not count.... sadly my meter is installed before... the contactless / transistor pulse output is behind a sealed cover, i can get connected to it for the charge of an hours work plus make me laugh that one pulses 500 times for each kwh... hte optical does 10000 for each kwh hour.... so makes it easy to pick which one i like.... 

some meters also talks back to the company on what i belive they call LON network... ie it uses the power lines to talk to a central hub at each transfomer station which then has some equipment to talk over either high voltage lines or fiber net or maybe even phone lines.. who knows on that part.... 


could be fun if we could tap in to the info that goes back....regadless of what is beeing messured

boelle's picture

Re: Cracking Gas metering

not an bad idea... there are so many meters and so many ways to get data out of them.... 


problem with creating a thread is that it will sooner or later get filled up with info not needed there.... so a kind of thread then the info is copied over to a blog when its agreed the way to read a meter is fast, easy and reliable... 


Also this needs some that are willing to help out cracking the nut on each meter type.... we are not all experts, my own weakness is that i can get a heap load of ideas but not always knows how to execute



boelle's picture

Re: Cracking Gas metering

ahh think my meter talks back using ISO/IEC 14908-1 (a.k.a. LonWorks). Echelon made that i think they can spit out how to catch the data

Jérôme's picture

Re: Cracking Gas metering

I begun gathering related threads here:

I just searched quickly for "gas". Another search with "pulse" will bring a bit more results. Water monitoring threads are linked, just as everything measured by pulses.

Feel free to reorganize / remove useless links / rename links / extract useful info to the page.

salomon's picture

Re: Cracking Gas metering

Hi Folks.   New member to this forum. Looking for gas meter advice?

   I have ITRON SC6 gas meter as pictured below has anyone worked out how to  pulse meter for  this type of meter?

   Many Thanks.



GJPickard's picture

Re: Cracking Gas metering

Schlumberger R5 imperial gas meter info

I have one of these in my house (must have just missed decimalisation) -  Not my photo but mine is the same.

I have been meaning to have a look at the RJ11 port underneath for a while and finally had a tinker on Sunday.  The port is under the dial facia, under the BG sticker you can see on the photo.

I plugged in an old modem cable that had pins 2 - 5 broken out and then connected up 2 and 5 and then 3 and 4.  Nothing on 2/5 and I had a switch normally open on 3/4. 

The switch was closing from the 10 o'clock to just after 12 o'clock positions and looked pretty stable on my little multimeter (I had a couple of AA for the power source).  As they say your mileage may vary for how the switch is closed for.

The issue with the meter might be its slow pulse rate.  It is apparently 1 pulse per cubic foot of gas.  In practice it is around 1 minute between dial rotations/pulses when my boiler is on.  I will try and get a pulse counting arduino linked into the meter to see how clean the pulses are of they will need a healthy bit of debouncing.

As the pulses will be quite infrequent, my thoughts at the moment are that I could do with:

a.   An incrementing pulse count

b.  An on node flow rate calculation - possibly using a cheap RTC module to deal with the issue of the 32b timer not running whilst sleeping

Has anyone tried using building in an RTC yet for pulse counting?




Peter Galbavy's picture

Re: Cracking Gas metering

Just waiting for my EmonPi Solar PV kit and want to add gas monitoring to the mix. I also have an R5 meter.

From my naive view of the docs on the web-site I need to hack up an RJ11 ro RJ45 cable - not using any other sensors apart from the current clamps and Ac-Ac as supplied on the EmonPi - so that the RJ11 pins 3/4 go through to pins 2 (5V) and 6 (IRQ1/D3) but given the slow nature of the pulse I am not sure this will work.

Has anyone else hooked up an R5 to an emonPi rather than a emonTX?


magnayn's picture

Re: Cracking Gas metering

I'm interested in this, having just noticed the RJ11 port.

1 pulse for 1cuft doesn't sound too bad, as (if my sums are right) that's about 0.3kWh.

I'll probably prototype on something high-level like an rPI or a beaglebone as I've got these lying around. One thought is you could probably use an ESP8266 wifi module to do the whole thing - use the sleep mode and GPIO to wake the module and increment the count. I'm not sure how hard that'd be as I've not touched these modules.



GJPickard's picture

Re: Cracking Gas metering

Sorry should have followed up on my post ages ago

I ended up running a cut up modem cable (RJ11?) to the plug under the dials on my R5 which involved peeling away a sticker.  I then have this running into a moteino ( via one of the spare interrupt pins

There is small circuit involved to add in a pull up resistor, see here

I seem to recall it was a bit temperamental and I needed to redo some soldering - I suspect the very low current means you need to take a bit of care on the joints

The sketch needs a bit of work as the "power" bit is way off but the pulse count/battery bits all seem fine though.  The main issue is that if you swap batteries your count restarts.  I seem to be getting 1 year out a set of 3 AAs.

For testing I would just use a jumper cable to simulate the dial rotating as it is way too slow and a lot more comfortable doing this in front of the PC than hovering around in a cold garage

Arduino sketch attached hopefully

Good luck 


chrisghz's picture

Re: Cracking Gas metering

Hi, Newbie to the forum.

I've been trying to get my head around gas monitoring to go with my energy monitoring system I've got set up. Currently I use the Currentcost for electricity monitoring but I'm changing over to the emontx v3, and want to get the gas monitoring working. I have a GWI/UGI G4 Gas Meter and so far can't seem to get a magnetic pulse either from Hall effects or reed sensor. I did a video of the fast wheel turning and it looks like the "0" digit has a mirror in it. I'm guessing an IR reflective sensor would do the trick. Has anyone else got experience with the gas meter? I've also spotted in a little circular window a rotating blue encoder looking thing not sure if this is relevant?

I've included a picture of the meter and the zero digit.

Many Thanks

Robert Wall's picture

Re: Cracking Gas metering

You could try a magnetic compass around the least significant digit or around that box below the decimal part of the register - that would be more sensitive than a reed and possibly a Hall effect device. If that can't see a magnet, then you're looking at optical - that could be costly in power and pretty much rules out battery operation.

Unless you know the calibration of the other indicator, the register is the only meaningful indication that you can use.

daturach's picture

Re: Cracking Gas metering

I use a CNY70 optical sensor with a Schmitt Trigger (ST). You need to adjust the resistors on the ST. Once done, it works perfectly. On the software side (Arduino), the ST triggers an interrupt on the falling edge. On my gas meter, the reflective piece is located on the "6" (type BK-G4).

There are lots of info on Internet around this setup.


Bra1n's picture

Re: Cracking Gas metering

I've not done it with that particular gas meter but mine is similar and has a mirror in the hole in the '6' so I built a circuit to generate a pulse built around an SG-2BC opto-reflector details here

stuart's picture

Re: Cracking Gas metering

Bra1n's picture

Re: Cracking Gas metering

The link is about capturing the movement of a rotating dial and looking at the pictures posted by chrisghz his meter doesn't appear to have one

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