Analog water flow sensor

Projects General Guidance
1

Hi everyone,

I need your advice on a possibly simple question. I've got an analog water flow meter, the model is FM015R-SZ and this is the datasheet

https://www.belimo.eu/pdf/e/FM..R-SZ_datasheet_en-gb.pdf

I want to calculate the water consumption in a given period (e.g. 10min or 1h). The output of the sensor is given at lt/s

How do I measure the water consumption with analog sensors? I have experience with digital sensors where the manufacturer usually provides the ticks per liter (so I have to measure ticks or pulses)

In the case of the analog sensor, if I need for instance to measure the water consumption for a period of 5min what is the procedure in terms of programming I should follow? I have to just read the analog input every 1s and accumulate the readings for the period of 5min?

Thanks in advance

2

Take the average of the flow over your measurement time, then total flow becomes: (litre/min)*minutes . Or whatever units you have

3

You will need a voltage divider to lower the 0.5 to 10V output to suit your unknown Arduino.

4

JCA34F:
You will need a voltage divider to lower the 0.5 to 10V output to suit your unknown Arduino.

...and make sure the divider doesn't draw more than the specified 1mA.

5

JCA34F:
You will need a voltage divider to lower the 0.5 to 10V output to suit your unknown Arduino.

I have taken care of the hardware part, thanks!!

aarg:
...and make sure the divider doesn't draw more than the specified 1mA.

xm.. thanks for your advice, I didn't consider voltage divider's current..

hammy:
Take the average of the flow over your measurement time, then total flow becomes: (litre/min)*minutes . Or whatever units you have

But in case I take the average flow, the total consumption over time won't be as accurate, isn't it?
The scenario of reading the flow every second and just aggregates the values over time?

6

You have a flow rate meter, not a totalising meter -you have to decide how often you read the meter and average the reading to get the result you want -there is no way around this.

7

hammy:
You have a flow rate meter, not a totalising meter -you have to decide how often you read the meter and average the reading to get the result you want -there is no way around this.

Thank you for your support hammy!! For example, if the readings are every second then I have to aggregate the readings every second, then divide by the total readings (to calculate the average water flow) and finally multiply by the time (to receive liters), isn't it?

8

Sounds about right

9

Thanks!!

10

Gey a bucket
Run on full open for 60:00:00 seconds
Again but at 50% open for 120 seconds
Then at one quarter open for 4 minutes.
If each fills to the same level
Then it is linear.

If your results are as you expect then your confidence of a accuracy will be high.