ESPHome pulse counter for water consumption

ESPHome
1

This question can be placed in several categories, but because I am using ESPHome for this, I will put it here.

I have a watermeter, if I am well, it is a Elster V100.
This meter has a hole for a reed contact sensor. In the specs I have found a value of 0,5 liter per pulse.
I have put a reed contact sensor in the hole and connected it to an esp32 board.

With ESPHome I have created a pulse counter to get the used water in m3, so I can read this and connect it also with the energy dashboard.

It is working, but the values are not quit correct.
Every day I check the water meter and the measured value in Home Assistant.

The strange thing is, that the value in Home Assistant is every day 1,4 times volume as shown by the watermeter.

In ESPHome I assigned 0,0005 m3 to one single pulse (0,0005 m3 = 0,5 liter).
But because HA shows 1,4 times the real value, I actually should change the value per pulse to 1 / 1,4 * 0,5 = 0,35714, which seems a strange value to me…

Can someone explain this odd value? I did not set anything for raising or falling edge, so can the problem be with that?

sensor:
  - platform: pulse_counter
    pin:
      number: 12
      inverted: true
      mode:
        input: true
        pullup: true
    name: "waterflow_pulse"
    unit_of_measurement: 'm³/min'
    update_interval: 10s
    total:
      unit_of_measurement: 'm³'
      name: 'waterverbruik_pulse'
      device_class: water
      state_class: total
      accuracy_decimals: 4
      filters:
        - multiply: 0.0005
2

filters have also calibrations as an option,

3

Thank you for your quick reply!
I can change the value, or as you told me, use a filter to calibrate.

I am only wondering, is it possible that a meter is so much off of the specs (0,5 liter per pulse)?

4

My first guess would be it’s an Imperial/Metric conversion issue. I know you said you found specs giving a metric value, but I wouldn’t be surprised if there’s a version of the same meter for the North American market and perhaps you somehow ended up with one? A quick Google search says Elster is owned by Honeywell, which is definitely an American company.

But like I said, it’s all a guess. If your conversion is working…

5

0,1 gallon equals 0,3785 liter
So that comes already pretty close to what I calculated as consumed liter per pulse in my case:
0,35714

6

I think you are facing the problems I had before… I tried with 5(!) different sensors and ESPhome. the problem is simple… I f the wheel stops right below the sensor or right next to it, it counted “doubles”.

When I installed a homewizard watermeter it workd for me (no esphome).

7

That was another thing I was thinking of.
I am only wondering why the difference is almost the same every day (1,4 times)…

8

That seems pretty close. Also might want to compare liters to cubic feet, which is also a common unit for measuring water usage in the US.

9

Did you manage to get this working? Where did you buy the sensor?