Need analog signal please help

[Durdy]

Gents,

Here is the deal, I have Flow meter FHKU 100 installed on disinfection system. The flow meter have +8V, GND and IN connections on control panel, and displays flow rate on control panel.
I need an analog input (+,-) to the system to control the disinfection rate 0-20 mA or 4-20 mA. It will be perfect if i can get this signal from flow meter proportional to flow rate, meaning maximum flow 20 mA, no flow 0 or 4 mA.
Is there any way to convert or get parallel signal from this flow meter.
thnx in advance.
cheerz

 

[itsmoked]

You are asking for a pain in the rear usually.

You should use a "Process Controller".

They are pretty cheap and let you make adjustments and run PID control algorithms, etc.

ExampleMany many many available)

http://web2.automationdirect.com/adc/Overview/Catalog/Process_Controls

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[danw2]

According to web specs for the FHKU 100, it has an open collector, pulse output, with the somewhat odd pulse rate of "approx. 65 Imp./ l (Nozzle 10mm)" [im]pulses per liter?

http://www.gsg-e-shop.de/onlineshop_e/onlineshop/index.html?d_FHKU_FHKU3034.htm

So, in answer to your question, if your controller needs an analog signal, you might consider
a) getting a flowmeter that outputs flow rate directly as an analog signal.
b) converting the open collector pulses to an analog flow rate signal with a frequency converter, a pulse-to-analog converter

Devices like the Precision Digital PD693 panel meter takes an open collector input, displays the flow rate and with an optional analog output provides an isolated 4-20mA flow rate signal.

http://www.lesman.com/unleashd/catalog/digital/digind_pd692.html

Or the Phoenix Contact MCR-f-UI-DC, 2814605 is a DIN rail mount frequency converter, but it requires a software programming kit and cable to scale the output.

http://www.phoenixcon.com/products/interface/db/level1_2.asp?l0=MCR&l1=Frequency%

Or there are a hundred other I/O manufacturers' frequency converters that will do the job.

Dan