Common use is for the 2-wire pulse-output flow meters on irrigation mainlines.
You can use EKM Metering’s 2-wire pulse-output water meters on an irrigation mainline. $70.
You can push flow data to cloud with wireless pulse counters and cellular or ethernet gateways. I’ve used Monnit’s hardware for this purpose.
Also I’m experimenting with 3-wire hall-effect flow sensors which are much cheaper and can also be used with some additional low-cost hardware.
Here is a Monnit setup I’m currently using:
http://tinyurl.com/gwslwg6
Wireless signal from pulse sensor dropped a little after moving pulse transmitter 150ft. to backyard next to irrigation controller and pump. .
I’m using a 3-wire hall-effect flow sensor and an Arduino Uno board to bring signal to a Monnit wireless pulse counter.
Note that iMonnit Basic is free but only outputs raw pulses with the 4-input Multi Pulse Counter. Upgrading to Monnit Premier will allow scaling from pulses to GPM. Not really necessary as long as you want to look at just raw pulse output. I’ve haven’t had good success with the 1-input counters but I’m working with Monnit on this technical issue.