Hi I saw that a post on this forum partially solved my problem. I have a liter-counter sensor and I would like to use it by connecting it to arduino. I just don't know how
The information is in the sketch. They used pin 6. It might be best to get a book or two such as the Arduino cookbook and go through it, it will give you the fundamentals you need to understand what you read.
What exactly are you after? Do you want the Flow Rate such as liters per min or liters per hour (LPM, LPH) or gallons per min or Gallons per hour (GPM, GPH). Those would be flow rate. You can also have a Flow Totalizer function. The latter totalizer just tells you the quantity which has flowed. I did notice the following for your meter:
Electrical output: 0.1, 1 and 10 liter / pulse
What I have not found is a good decent data sheet? On flow metering devices the number of pulses per unit of measure is often referred to as the "K" Factor.