What is a volumetric water meter?

Working Principle

Water enters the measuring chamber from the water inlet, pushing a rotating piston around the central axis of the measuring chamber. As the piston rotates, water is expelled from the piston's interior and the space between the piston and the measuring chamber wall to the water outlet.

Each complete rotation of the piston displaces a fixed volume of water. A counting mechanism records the number of piston rotations, thereby accumulating the volume flowing through the meter.

Structural Features

A volumetric water meter utilizes a piston-type structure. Its core components include the piston, measuring chamber, rotating shaft, shift fork, and counting mechanism.

A chamber of known volume is formed between the piston and the measuring chamber, ensuring that the same volume is displaced with each rotation, achieving high-precision measurement.

Metering Advantages

High sensitivity enables accurate measurement at low flow rates (e.g., 1 L/h).

The counting mechanism is vacuum-sealed, ensuring clear readings over time. The high-quality movement materials ensure stable performance and a long service life.

Application Scenarios

It is primarily used in water supply systems requiring high measurement accuracy, such as purified drinking water and industrial water.

How to calibrate a volumetric water meter?

Calibration Model and Error Calculation

Volumemetric water meters use the volumetric method to determine the difference between the meter's indicated volume and the actual volume of a standard metal measuring vessel, correcting for the vessel's temperature coefficient.

Standard Apparatus and Experimental Procedures

Use a calibrated standard metal measuring vessel (e.g., a 20L stainless steel measuring vessel) as a reference to ensure that the measuring vessel's volume at 20°C is consistent with the standard value.

Connect the water meter to the standard measuring vessel via the calibration device, gradually inject known volumes of water, and record the cumulative meter readings.

Error Correction and Adjustment

Based on the calculated volumetric error, adjust the meter's counting mechanism or electronic compensation factor to ensure that the readings match those of the standard measuring vessel.

If the error exceeds the allowable range (e.g., ±0.5%), recalibration or replacement of the movement components is required.

Online Calibration Technology

Volumemetric water meters use an online calibration device that allows real-time calibration of valves, hoses, and other components during meter operation, ensuring long-term metering accuracy.