A water meter with an impulser, i.e. a work of automation - a partisan.

Well ... you have to save somehow. If there is nothing else at hand ... Clever

The system was not used for billing, so removing the seal was not a problem. By the way, it turned out that in newer water meters there is an insert made of some sintered powder around the magnetic clutch, shielding in the event of attempting to block the water meter with an external magnetic field. The dosing pumps have an input on the NO contacts, so the reed switch has the advantage over the hallotron that it does not need power. I could have even less interference in the water meter and mount on it a small reflective sensor (it was at hand) that would work with a counter-painted water meter (3/4 black matte, 1/4 mirror), but it would require pulling a 10m 24V power supply from the neighboring the room, where there is a boiler control cabinet with a power supply, and adding a relay to control the pump. The customer was, of course, informed about the application of such a solution and agreed to it. In the event of failure, replace the commercially available water meter with reed switch.

Hehe. The supplier well known to me, actually one of the most interesting sensor sources at good prices. Only 100km one way. In addition, as I have already written, a primitive water meter with no-reed contacts is enough to control the dosing pump. Price approx. PLN 100. It's just that the topic was urgent, and on this spill they are not in any shop within a radius of 30km, and go to Łódź or Wawy me not calculated (fuel cost comparable to the cost of a water meter, I will not mention the time).