Differential flow meter | Types and principles of flow meters

『Dynamic differential flowmeter』Related information(clamp on meter|electromagnetic meter|venturi meterrotameter|orifice meter|ultrasonic flow meter|mass flow meter|coriolis mass flow meter|coriolis flow meter|magnetic flow meter|magmeter flow meter|magflow flow meter|mag meter flow meter|electromagnetic flow meter|vortex flow meter|turbine flow meter|thermal mass flow meter|thermal flow meter|rotameter flow meter)

1. How to read flow meters There are many types of flow meters, which can be roughly divided into several categories, about hundreds or more. But no matter what form of industrial instrument it is, it is definitely a user-friendly interface that allows you to understand at a glance. The general distinction is briefly introduced below for reference.

1. Classification according to measurement principles: (1) Mechanical principles: differential pressure type and rotor type using Bernoullis theorem; The impulse equation and movable tube equation using the momentum theorem; Using the direct mass formula of Newtons second law; Target based on the principle of fluid momentum; Turbine type using the angular momentum theorem; Vortex type and vortex street type utilizing the principle of fluid oscillation; Utilize pitot tube type, volumetric type, weir, trough type, etc. that utilize the total static pressure difference. (2) Electrical principles: electromagnetic, differential capacitive, inductive, strain resistive, etc. (3) Acoustic principles: ultrasonic, acoustic (shock wave), etc. (4) Principles of Thermodynamics: Thermal, Direct Calorimetry, Indirect Calorimetry, etc. (5) Optical principles: Laser and photoelectric instruments belong to this type of principle. (6) Based on physical principles, instruments such as nuclear magnetic resonance and nuclear radiation belong to this type of principle. (7) Other principles include labeling principles (tracer principle, nuclear magnetic resonance principle), related principles, etc.

2. Classification according to the structural principle of flow meters. Based on the actual situation of current flow meter products and the structural principle of flow meters, they can

be roughly classified into the following types: 1. Positive displacement flow meters are equivalent to a standard volume container. The principle of positive displacement flow meters is relatively simple and suitable for measuring high viscosity and low Reynolds number fluids.

. According to the different shapes of the rotating body, the products currently produced are: elliptical gear flowmeter suitable for measuring liquid flow rate, waist wheel flowmeter (Roots flowmeter), rotary piston and scraper flowmeter; Servo volumetric flow meters, diaphragm flow meters, and rotary flow meters suitable for measuring gas flow. 2. The working principle of impeller flow meters is to place the impeller in the measured fluid, rotate it under the impact of fluid flow, and reflect the flow rate by the speed of impeller rotation. Its structure can be mechanical transmission output type or electric pulse output type. The accuracy of water meters with general mechanical transmission output is relatively low, with an error of about ± 2%, but the structure is simple and the cost is low. The accuracy of the turbine flowmeter output by the electric pulse signal is relatively high, with a general error of ± 0.2% to 0.5%. 3. Differential pressure flowmeter (pressure drop flowmeter) Differential pressure flowmeter consists of a primary device and a secondary device. It receives the differential pressure signal generated by the measurement component and converts it into the corresponding flow rate for display. This method of measuring flow using differential pressure has a long history and is relatively mature. It is generally used in important situations around the world, accounting for about 70% of various flow measurement methods. This typ

『SILVER Official Website SERVICE』