Hi everyone,
I'm searching for flow meter (or energy meters) that has Mbus interface output. Could you please suggest some devices to me?
some properties;
-can be used for clean water
-should be non invasive
-should be cheap
-easy to carry

Thank you!

you'll have to shop your specific requirements, but here's someone else's list:
http://www.hw-group.com/products/HWg-PWR/M-bus_met...

If your meters have RS232 or RS485 comm ports you should be able to buy an interface device that can do mbus. I connect power meters via RS485 ports to a device that can talk MODBUS to the control systems.

Can you suggest one such device so that I can understand the idea?
and danw2, thank you very much also =)

I'm not sure there's a device out there that meets your spec, because even though M-Bus sees wider use in European than in the US, I would expect any instrumentation performing the tasks you list to show up in the US, and I haven't seen them yet.

I still get involved with relatively expensive clamp-on (non-invasive) ultrasonic flow meters for permanent installation used for BTU billing for utility chilled water. The temperature measurements are done with 4 wire, matched pair RTDs to get the accuracy needed for the temperatures.

The kit is not cheap, not easy to carry, but it is non-invasive.

If you find something does in fact meet your requirements, please me know in reply. I'd do something to deal with M-Bus if a product like what you propose is out there.

CEWE prometer R energy meters can be connected with a specialised device (you can find it if you google CEWEmod).

I also use a fairly new device manaufactured by a small UK company (http://www.kenda.co.uk/kenda/nebula.html) that can be ethernet connected and talk MODBUS. They aren't cheap though.