Measuring the volume of material in the field, fluid flow is the detection and control of all walks of life to strengthen materials management, energy management, material transfer, financial settlement, economic accounting, benefit analysis and evaluation until an important basis for decision-making; enterprises is also monitoring the production process To the protection of high quality, efficient, safe and stable operation and an important means of improving the environment. In a certain sense: measurement is the eyes and measurement is money, efficiency is measured. Modern enterprises to measure the flow of increasingly demanding high, reflecting mainly to meet the accuracy, reliability, timeliness and the extent of the level of automation, and so on.


1 several commonly used measurement method outlined

In order to meet the needs of the various measurements, for hundreds of years people according to different measuring principle, research and development has manufactured dozens of different types of flow meters, roughly divided into volumetric, speed-and-differential, the area of quality - And so on. Various types of flow measurement principle, structure both unique and different limitations. In order to achieve a better measurement results, the need for different measurement, the measurement of different media and different scope of work, the choice of different types, different models of the flow meter. Industrial measurement commonly used in several gas flowmeters are:

(1) Differential Flowmeter

Differential Flowmeter is Bernoulli's equation and fluid continuity equation as the basis, in accordance with principles of cutting expenditure, when fluid flows through the expenditure of time (such as standard orifice, the standard nozzle, the length of the nozzle, classical Venturi mouth, Venturi Lee nozzles, etc.) before and after a pressure drop in his, with the value of this differential pressure flow is directly proportional to the square. In Differential Flowmeter, cutting expenditure by Standard Orifice devices Pressure Meter simple structure, low manufacturing costs, the full study, standardization has been the most widely used.