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Flowmeter Setup to DAQ Assistant

Im trying to acquire data from Omega Flowmeter FLR D Series, but havent been succesful in the setup through Labview, any help would be appreciated.



Anton Gomez

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Message 1 of 8

It says it has Analog outputs.

Do you see voltage (or current) on these analog outputs with a regular multimeter?

What are you using as Analog inputs on PC?

How did you configure acquisition hardware? You can post your test VI here, data and errors it gives you.

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Message 2 of 8

Thanks for your response.


The flowmeter has 4 possible wiring schematics. The power  supplies 22VDC to the flow meter. In my understanding this should output 0-5 V. I'm not receiving that. 


For the hardware I have available DAQ assistants NI 9203 or NI 9205. 

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Message 3 of 8

So what is not working?

Sensor does not output data? Do you have multimeter to check?

9203 measures current, 9205 measures voltage, they are connected differently. If you connect AA battery to 9205, will you get 1.5 V? 

If I was not sure in all parts: sensor, connections, communication with DAQ board, I would check them one by one.

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Message 4 of 8

Sensor outputs voltage signal but not in the range of 0-5V. Do I have to scale the output voltage?


For example for lower flow rates it measures mV and higher flow rate 1 V. 

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Message 5 of 8

It is always good when signal uses full scale. You specify ADC range (internal amplifier) when you configure acquisition, you can set +/- 1 V range. Theoretically you can switch it - stop acquisition, change scale, start acquisition if you get out of range.


Though +/-5 V range, 16 bit resolution = 0.15 mV on one bit, you need to have really good wiring, isolation, temperature control, etc to start caring about precision loss due to resolution. 

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Message 6 of 8

For better visualization I achieved a flow rate of ~4.5 GPM in both flow meters. Voltage reading from labview is ~1.9 V. As seen in figures. 

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Message 7 of 8

@gomezanton wrote:

For better visualization I achieved a flow rate of ~4.5 GPM in both flow meters. Voltage reading from labview is ~1.9 V. As seen in figures. 

You should specify what is the range of your flow meter. For example, if your FM has a range of 0-50 GPM, 0-5 VDC output, then a 2.5 Volts reading means 25 GPM. This applies if the manufacturer used a linear scaling (most usual approach).

By the way, you do not need to make a photo with your mobile, you can create screenshots from any OS:


But the best if you share your actual VI, so we can check the settings are OK in your code...

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Message 8 of 8