Being inspired by Bart's blog on the watermeter, i wanted to try it myself. I live in the Netherlands and have a watermeter from the company presikhaaf, i could not find a type number. Perhaps someone recognizes the meter from the photo.
Unfortunately my meter does not have a small opening for hall sensors as Lieven had, this already made me a bit worried. To test my meter I made a smaal setup using components from phidgets. They have easy to use analog input devices and a hall sensor board containing a Allegro A1321 hall sensor, not a hall switch! Using the api from phidgets i made a small java program to draw a graph of the signal. Testing with a magnet showed nice graphs.
Using this i went to the watermeter, opened a tap to let some water flow and started to move the sensor around the meter. Nothing :-( Where ever i put the sensor, in any direction, no clear signal. So no luck for me. To be absolutly sure i bought a real hall switch, i could not find the A3214 Bart and Lieven uses, but instead use the TLE4905L which is also a cheap hall switch. A few components according to the datasheet, i made my own sensorboard. But again, no luck in measuring any magnetic activity around my watermeter.
Being near the gasmeter too, i held the hall sensor and the hall switch also to the gas meter, again no luck. it seems that at least my Dutch water- and gasmeter are not equipeted to be measured via hall sensors.
The gasmeter though has a spining wheel with white and black stripes, i want to see if i can make a optiocal detector to see that movement. The watermeter also has a small wheel in the center, but that has no color stripes and i do not think i can measure that optically.
So no luck for me, but perhaps someone else can use my experiments to see if they do have a magnetic capable watermeter and/or gasmeter.
The watermeter could perhaps be monitored using the microphone. Anyone some ideas about that? Especially some easy software to process the signal.