News Center
We are dedicated to providing users with cost-effective instruments and meticulous services! Welcome to visit, guide, and negotiate business with us.
Current Position:
Home > News > Technical Support

How does Aister instruments manufacturer choose a good gas flow meter? What are the criteria?

2021-05-26

How do customers choose a good gas flow meter, the following Aister instrument manufacturers to talk about.

Gas flowmeter must choose a good brand to use the convenience. Selection is generally considered from these three points, that is, according to the nature of the measured flow body and flow conditions to determine the flow sampling device and the type and specifications of measuring instruments, selection should be fully in line with the instrument conditions provided by the process, considering the accuracy level and economy.

1. according to the nature of the measured flow body and flow conditions, to determine the type and specifications of gas flowmeters

The nature and flow of the fluid determine the form and specifications of the flowmeter. First of all, the selection should consider several key physical and chemical properties of the fluid: the state of the fluid (solid gas or liquid), the conductivity of the fluid, the chemical corrosion of the fluid, and the viscosity of the fluid. Secondly, it is necessary to fully understand the application range of various forms of flow meters. The physical and chemical properties of the fluid should be considered comprehensively in the selection. The fluid in the solid state is generally dust or block strong, and the flow meter selection is only three kinds of impulse flow meters, belt weights and track scales. There are more forms of flow meters for liquid and gaseous fluids, and general flow meters have series and models dedicated to gas measurement, such as the Coriolis force mass flowmeter we use has series models dedicated to gas measurement. If the liquid working condition is relatively poor, it is not exhaled corrosion, conductive, and with solid particles, in this case, it is best to choose the electromagnetic flowmeter. The flowmeters suitable for high viscosity mainly include elliptical gear flowmeters, waist wheel flowmeters, scraper flowmeters, target flowmeters, wedge flowmeters, etc., which are also determined according to accuracy, economic requirements and other actual working conditions. * After the corrosion of the fluid in the selection of the flow meter must pay attention to the choice of liquid material, for example, when the electromagnetic flow meter is used to measure hydrochloric acid liquid electrode must be used tantalum electrode otherwise the electrode is easily corroded.

2. the choice of gas flow meter should fully consider the table conditions provided by the process.

First of all, consider the static pressure and temperature of the medium, the static pressure and temperature resistance of the flow meter is also an important part of ensuring the service life and accuracy of the instrument, the static pressure of the instrument is the degree of pressure resistance, it should be slightly greater than the working pressure of the measured medium, generally 1.25 times, to ensure that there is no leakage or accident.

The second is the choice of the range range, mainly the choice of the upper limit of the instrument scale. Select small, easy to overload, damage the instrument; The selection is too large, which hinders the accuracy of measurement. The national standard stipulates that the maximum flow does not exceed 95% of the full scale; The normal flow rate is 70% ~ 85% of the full scale; The minimum flow is not less than 30% of the full scale. The more important instrument condition is the process pipe diameter, some flowmeters do not have a particularly large diameter, some large diameter flowmeters are very expensive, currently more suitable for large pipe diameter flow meters are flute uniform tube, insert vortex, insert turbine, electromagnetic flowmeter, venturi tube, ultrasonic flowmeter.

3. Consider the accuracy level and economy of the gas flowmeter

Generally, where the accuracy requirements are relatively high, there are mainly raw material measurement into the factory and into the production device, the finished product measurement of the output device and the factory sales, the measurement of raw materials of the process formula, and the measurement of expensive substances. For the flow rate that is only a general reference in the production unit, cheap flowmeters such as glass rotors and metal rotors are usually selected with relatively low prices. The gas (air, nitrogen, vapor) in the production of public works usually uses vortex flowmeters, and all kinds of water mainly uses electromagnetic flowmeters. These two options are economical and can meet the accuracy requirements.

艾丝特气体流量计
Share To: