Recently purchased a flow sensor FS3400AH from Futurlec, specs are limited, 0.050.5 LPM with an open collector output.
It's a 3 wire flow sensor (+/ and signal wire), compatible with gas/diesel, have manged to figure out that in order to generate a usable waveform the sensor signal output and power feed wires need a resistor between the two, waveform generated is a duty cycle type of square wave, that depending on flow, increases / decreases respectively.
I assume there is some sort of a math formula that could be applied to the software that would take it from a square wave and convert into a reading that give the flow (LPM) and not the duty cycle / voltage output.
Complete transparency, the math function of Pico is great but is not my strong point, I'm hoping someone has or can use the attached file and create the formula that would allow this sensor to be used as a monitor of flow, not just a wave form generator.
Thanks
Flow Sensor  NON Webtec
Flow Sensor  NON Webtec
 Attachments

 Flow Sensor Test 202012110001.psdata
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Re: Flow Sensor  NON Webtec
Hello,
Use integral(freq(A))*0.0005 to find the volume
Best regards
Use integral(freq(A))*0.0005 to find the volume
Best regards

 Pico Staff Member
 Posts: 1020
 Joined: Sun Aug 25, 2013 7:22 am
Re: Flow Sensor  NON Webtec
Hello and thank you for the posts
I have been looking for the specifications of your Diesel and Gasoline flowmeter @ Futurlec but could only find the data sheet for FLOWFUEL30L0 which has a 2.0  30 liter/hour flow rate. (Finding the spec sheet will help enormously)
Using these specs below @ 0.00050 liter/pulse
0.0005*1000 = 0.5 ml/pulse
Therefore the frequency (not duty) of these pulses in Hz (cycles per second) multiplied by the volume per pulse (0.5 ml) will find volume in ml/s
Now multiply by 60 to convert ml/s (milliliters per second) to ml/m (milliliters per minute)
Finally divide ml/m by 1000 to find l/m (liters per minute)
The match channel would be entered as Freq(A) x0.5*60/1000
I have applied the above math to your capture (although this does not apply to your flowmeter) just to show the outcome
I hope this helps, take care...Steve
I have been looking for the specifications of your Diesel and Gasoline flowmeter @ Futurlec but could only find the data sheet for FLOWFUEL30L0 which has a 2.0  30 liter/hour flow rate. (Finding the spec sheet will help enormously)
Using these specs below @ 0.00050 liter/pulse
0.0005*1000 = 0.5 ml/pulse
Therefore the frequency (not duty) of these pulses in Hz (cycles per second) multiplied by the volume per pulse (0.5 ml) will find volume in ml/s
Now multiply by 60 to convert ml/s (milliliters per second) to ml/m (milliliters per minute)
Finally divide ml/m by 1000 to find l/m (liters per minute)
The match channel would be entered as Freq(A) x0.5*60/1000
I have applied the above math to your capture (although this does not apply to your flowmeter) just to show the outcome
I hope this helps, take care...Steve
Re: Flow Sensor  NON Webtec
Thank you for the math lesson, can I assume that if I want the reading in ml/m I would drop the /1000 off the end of the formula..?
Neil
Neil
Re: Flow Sensor  NON Webtec
I contacted the company that sells the meter and included the full specs they sent, looks as though Steve's research was spot on..
Features :
Diesel and gas application
2.0 – 30 liter/hour flow rate
Accurate and reliable
2.0 Electrical :
Supply voltage : 2.4 – 26 V DC
Supply current : typical 2.8 Amps, maximum 8.0 Amps.
Output mode :open collector
Output rise time : typical 1.0μsecond. maximum 10μsecond.
Output falling time : typical 0.3μsecond. maximum 1.5μsecond.
3.0 Mounting method
Horizontal mounting, maximum 30 degree lifting.
4.0 Flow Rate : 2.0 – 30.0 liter/hour
5.0 Calibration :
Flow Rate(LPH) Liter/Pulse
2.0  0.00038
4.0  0.00050
12.0  0.00050
30.0  0.00050
Accuracy : +/ 10%
6.0 General :
Connection : 3/8” barb
Temperature : 0 to 60℃
Pressure : Max. 6.0 bar (85 psi)
Materials : Sensor Body : Acetal Copolymer (POM), TICONA M90
Turbine : Acetal Copolymer (POM), TICONA M90
Stick of Turbine : #304 Stainless Steel
ORing : NBR Thanks again for the help,