The principle of mechanical water meter mainly includes two methods: velocity measurement and volumetric measurement.
Velocity measurement
Rotor water meter: When water flows through the water meter, it will impact the impeller (rotor) and make the impeller rotate around the axis. The faster the water flow, the faster the impeller rotates, and the two are proportional. The linkage component on the impeller shaft is connected to the counting mechanism. Every rotation of the impeller represents a certain amount of water flowing through. The counting mechanism accumulates the number of rotations of the impeller through transmission devices such as gears, and converts it into the rotation of the pointer on the dial, thereby displaying the water consumption.
Propeller water meter: After the water flows into the water meter, it exerts an impact force on the spiral rotor, causing the spiral rotor to rotate around the central axis. The water flow speed is proportional to the speed of the spiral rotor. The rotation of the spiral rotor is transmitted to the counter through the transmission mechanism. The counter records the number of rotations of the spiral rotor and then calculates the amount of water passing through the water meter.
Volumetric metering
Piston water meter: It is mainly composed of a housing, a metering chamber, a piston or diaphragm, a counter, etc. When water flows into the water meter, the piston or diaphragm is pushed to move under the action of pressure. Each movement will cause a certain amount of water to enter or exit the metering chamber. By counting the number of times the piston or diaphragm moves, the total amount of water flowing through the water meter can be calculated. The amount of water corresponding to each movement is fixed, and the number of movements is proportional to the total water consumption.