Gasmeter RF1-G4 again...

Hello everybody!

I have a (Schlumberger) RF1-G4 at home (Brussels) and I spent most of the week-end to try to get some pulse out of it with a reed sensor without any success at all...

Here is a picture of the meter:
(I used an Arduino board to detect the pulse)

So does anyone know exactly where the magnet is located? (which digit?)
(It says 1 pulse / 0,1m3, so it should be on the 2nd decimal...)

Maybe my reed switch is not sensible enough, I tried with what I had in my stock...

Other option would to test with hall sensor, just need to find a good one... (and Farnell is a pain for private users :( )

Any hint appreciated!

on3ptz's picture

I think that the open space on top of the meter is the place where the sensor must be installed.

if you don't find it, i can come to your place to help.



Amedee's picture

Tnx Bram,

Yes I tried this place as well, as it is where the 'official sensor' is supposed to go...

I guess my reed relay is not sensitive enough. I'll try to find a better reed or a hall sensor.

It is probably the same with my watermeter btw ;)

Thank you as well for you on-site help proposal -- I'm tight to work this week, but I may ping you after XMas!



Amedee's picture

Just to follow-up on this...

(It takes some time to test as 0,1m3 is already a lot of gas and I don't want to 'burn' gas just for testing, so I wait long enough until we actually use it ;) )

I tried again with another reed switch, but could not get any pulse...

So I started measuring with a hall sensor, and this is working much better, the sensor goes 'South' in front of the digit '6'.

Next step is to replace the hall sensor with a hall switch and connect it to the Flukso box...

nico_poussin's picture


I m in the exact same situation, I just spend 2 hours in my garage trying to find a pulse.
I m using a reed swith on the G4 RF1 gas meter.
According to your test this is not the good solution. Can you tell me which sensor was working for you ?
Did you find a working hall effect switch ?

Thanks for your help.


Amedee's picture

Well, some people have it working with reed switches, but the ones I have at home are just not sensitive enough to detect the pulse...

And I tend to agree you, when you start and don't know exactly where to look at it is a bit frustrating -- meters are usually not in the most accessible / comfortable place in the house ;)

Anyway, I had a hall sensor that I was using in Arduino experiments, so I initially used it to locate and 'measure' the pulse, so at least it confirmed my meter was well equipped with a magnet.

Now for the Flukso box, a hall 'sensor' does not help, you need a hall 'switch'. After reading the articles [1] on Flukso and [2] on, I went for the Allegro A3214, and it is working very well.

The advantages of this switch is that it is sensitive, omnipolar, does not use a lot of energy and can be powered directly by the Fluksometer.


icarus75's picture

Just to clarify Amedee's approach: If you leave the RS485 port disabled, the 'a'-terminal will provide you with a 3.3V current-limited rail to power the Hall switch.