Hey guys,


I have a Futurmat Milady, E61 HX machine from 1993. It has volumetric dosing which used to work fine...

I am rebuilding and modifying the machine somewhat. I 've elongated the 3 wires going to the flowmeter and accidentally switched 2 of them. Now the volumetric dosing doesn't work anymore, no matter how I hook up the wires.

I've read that it's possible to test a flowmeter by measuring the resistance between the "+" and the "o" and that it should be 2.2 K Ohms: This checks out. Could the flowmeter still be shot? Or the board? How do I proceed in checking what the problem is?

Thanks guys!

Elwin

A while back, Bill Crossland (formerly of LM-USA) posted a link to a pdf of Digmesa flowmeters:

http://www.digmesa.com/en/classicline-products/flow-sensor-fh/

Now, this wasn't the exact link but I did save the particular pdf and one of the pages has installation tips which has, in part, the following sad info:

• Incorrect cabling of power supply +, signal and ground will destroy the flowmeter

You likely have a Gicar flowmeter but I just sorta assume the results would be the same.

Eric, thank you very much!

I do have a Gicar flowmeter so I can assume I destroyed it then. I'm getting a used one tonight from a friendly neighborhood espresso service tech, so I'll have him look at the connections on the board and how it should be wired before I hook it up.


Kind regards,
Elwin

Ps. Sorry for the cross-post! It won't happen again.

These meters are hall effect sensors with rotating magnets on the vanes, and the flow is determined by the pulse count on the spinning vanes.

A shorthand description is a chip that senses a magnetic field. Like any silicon based circuit you will kill them to death with a reverse voltage. The problem is that the sensor is in the epoxy top head of the body. If you kill that then you are shopping for a new flow meter.

-C