Using Vehicle Mass airflow sensor to measure flow rate

[ndemaio]

Hello, 

I have a 5 pin MAF sensor, see picture for wiring, and I want to use it to measure the flowrate of air. The MAF uses 12V and about .20 amps so I have a 30V, 20A DC power supply to power it. I don't really know a lot about LabVIEW so I'm here looking fore some help. For DAQ cards I have: NI 9210, NI 9482, NI 9203, NI 9265, NI 9263, NI 9205, and USB 6001. I have been trying to use the 6001 but it gives me a sine wave, from about -10 to +10. I looked a bit into the MAF and some output PWM signals, which I'm guessing that's what this is. if there is a better card that can supply power and take the measurements, or a better card for my purposes that would be helpful to know as well as how I can set up a VI to find the flowrate

Thanks

[GerdW]

Hi ndemaio,

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@ndemaio wrote:

I have a 5 pin MAF sensor, see picture for wiring, and I want to use it to measure the flowrate of air. The MAF uses 12V and about .20 amps so I have a 30V, 20A DC power supply to power it. 

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So the sensor needs 12V, <=0.2A supply, but you want to power it with a 30V, 20A power supply?

Do you think this is a good idea?

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@ndemaio wrote:

For DAQ cards I have: NI 9210, NI 9482, NI 9203, NI 9265, NI 9263, NI 9205, and USB 6001. I have been trying to use the 6001 but it gives me a sine wave, from about -10 to +10. I looked a bit into the MAF and some output PWM signals, which I'm guessing that's what this is. … how I can set up a VI to find the flowrate

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When you want to know which DAQ device you need to use then you need to read the manual of that sensor!

What about attaching that manual? What about telling us the exact type/manufacturer of that sensor? What about telling us the specifications of the output signals of that sensor?

Without specifications we cannot suggest a DAQ device!

[ndemaio]

Sorry I meant 0-30V and 0-5A, It's an adjustable power supply. I don't have and cant find a manual for this MAF or really any one. There is no real information from the manufacture that I can find, but there is info from people testing them and diagnosing them. I guess since its a car part, it is just supposed to be plug and play. This website I found has info on several different MAF's and they all output a 0-5 volt signal for measuring the flow rate. I believe the one I have outputs a sine wave, when i put it in one of the DAQs that's what it shows

https://autoditex.com/page/maf-lab-scope-waveforms-68-1.html

Specifically I have the "Delphi Mass Air Flow Sensor"  Part # AF10043

https://shop.advanceautoparts.com/p/delphi-mass-air-flow-sensor-af10043/20973820-p?product_channel=l...

[GerdW]

Hi ndemaio,

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@ndemaio wrote:

This website I found has info on several different MAF's and they all output a 0-5 volt signal for measuring the flow rate. I believe the one I have outputs a sine wave, when i put it in one of the DAQs that's what it shows

Specifically I have the "Delphi Mass Air Flow Sensor"  Part # AF10043

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Where do you see a "sine waveform"?

For me it looks very similar to Fig. 12 in the linked website, but the signal voltage range of ±10V seems totally wrong to me. How did you connect the sensor to your DAQ device?

If its really the case of "changing frequency with air flow" I would use a simple PCB with some electronigs to convert the signal to a defined TTL signal and then use the counter of your DAQ device to count the pulses or measure the frequency of the pulses!