How to ensure the accuracy of rotameters

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　　Take glass rotors for example; due to their easy installation, simplicity of use, and low cost, they account for the largest share of sales. All flowmeters have a measurement accuracy, which is what is commonly referred to as the range of measurement error. So what are the reasons that can cause larger measurement errors in float flow meters? 1. Improper installation: Generally, glass rotor flow meters are installed vertically, and the inclination angle of the meter during installation should not exceed 20 degrees. Of course, there are also some float flow meters that are installed horizontally; in such cases, it is necessary to keep the meter horizontal, with an inclination angle of no more than 20 degrees as well. 　　There must be no ferromagnetic objects within 100 mm around the float flowmeter. The installation location should be far away from valve diameter changes, pump outlets, and bends in the process pipelines. The requirement of a 5D front section and a 250 mm straight pipe section at the back must be maintained. 　　2. Gas media are highly affected by temperature and pressure. Flowmeters are calibrated before leaving the factory, with their flow rates set according to the temperature and density of the medium used by the user. Since gas media are greatly influenced by temperature and pressure, it is necessary for the user to provide accurate values for these parameters. 　　3. The density of liquid media varies significantly. Before calibration, the medium is converted to an equivalent density as specified by the user, so that the flow rate can be measured in terms of water under standard calibration conditions. Therefore, if the density of the medium changes greatly, it can cause significant errors in the measurements. The solution is to substitute the altered medium density into the formula to calculate an error correction factor, and then multiply the flow rate measured by the flow meter by this factor to obtain the actual flow rate. 　　4: Long-term use and pipeline vibration Various factors cause the moving parts of the float flow meter, such as the sensing magnet, pointer, counterweight, and rotating magnet, to become loose, resulting in significant errors. Solution: You can first verify by manually pushing the pointer. First, place the pointer at the RP position and check whether the output is 4 mA and whether the flow display shows 0%. Then verify it step by step along the scale. If any discrepancy is found, the position of the component can be adjusted. It is generally required that professionals make adjustments; otherwise, the position will be lost and it will be necessary to return to the manufacturer for correction. 　　Flow metering is one of the components of measurement science and technology, and it is closely related to the national economy, national defense construction, and scientific research. Flow measurement is widely used in various fields such as industrial and agricultural production, national defense construction, scientific research, foreign trade, and people’s daily lives.