Flow meters are further classified into differential pressure flow meters, rotor flow meters, throttling flow meters, slot flow meters, volumetric flow meters, electromagnetic flow meters, and ultrasonic flow meters. They are also classified by medium: liquid flow meters and gas flow meters.
Metrology is the eye of industrial production. Flow measurement is an integral part of metrological science and technology, closely related to the national economy, national defense, and scientific research. Doing this work well plays a vital role in ensuring product quality, improving production efficiency, and promoting scientific and technological development. Especially in today's era of energy crisis and increasing industrial automation, the status and role of flow meters in the national economy are even more prominent.
The commonly used unit in engineering is m³/h, which can be divided into instantaneous flow rate and total flow. Instantaneous flow rate is the amount of fluid flowing through the effective cross-section of a closed pipe or open channel per unit time; the substance flowing can be gas, liquid, or solid. Total flow rate is the cumulative amount of fluid flowing through the effective cross-section of a closed pipe or open channel over a certain time interval (day, week, month, year). The cumulative flow can also be obtained by integrating the instantaneous flow over time, so instantaneous flow meters and cumulative flow meters can be converted to each other.