Which is more accurate, metal tube float flow meters for gases or liquids?

Project Overview

As a commonly used flow measurement instrument, metal tube float flowmeter is widely used in gas and liquid flow measurement. However, the accuracy of measuring gases and liquids has always been the focus of the industry. First, we need to understand the working principle of the metal tube float flowmeter. It measures flow based on the principle that a float moves up and down in a tapered tube as the fluid flow changes. The displacement of the float is proportional to the flow rate, and the flow value can be read intuitively through an external indicator. This structure enables the metal tube float flowmeter to have a high measurement range and measurement accuracy.

When measuring gas, the accuracy of the metal tube float flowmeter is affected by many factors. First of all, the density and viscosity of the gas are low, which makes the movement of the float in the gas more sensitive and easily affected by factors such as air flow speed, temperature, and pressure. In addition, the compressibility of the gas may also lead to a decrease in measurement accuracy. Therefore, when measuring gas, the accuracy of metal tube float flow meters is usually low, generally around ±1.5%. Relatively speaking, when measuring liquids, metal tube float flowmeters have higher accuracy. The density and viscosity of the liquid are larger, making the movement of the float in the liquid more stable and less susceptible to external interference. In addition, the incompressibility of liquids also contributes to improved measurement accuracy. Therefore, the accuracy of metal tube float flow meters when measuring liquids can usually reach about ±1%, and even if there are special requirements, the accuracy can be higher.

In addition to the influence of fluid properties, the accuracy of metal tube float flowmeters is also affected by other factors. For example, the uniformity of the flow meter's cone, the shape and material of the float, and the accuracy of the indicator will all affect the measurement accuracy. In addition, installation and usage conditions will also have an impact on accuracy. Improper installation, impurities or bubbles in the fluid, etc. may lead to measurement errors. In order to improve the measurement accuracy of the metal tube float flowmeter, the following measures can be taken: First, choose a flowmeter with excellent tapered tube uniformity and high-precision float; secondly, ensure that the verticality is better than 2° during installation, and follow the correct Installation steps; finally, during use, regularly check and clean the flow meter to avoid impurities and bubbles from affecting the measurement. To sum up, the accuracy of metal tube float flow meters when measuring liquids is usually higher than when measuring gases. This is mainly determined by the physical properties of liquids and gases as well as the structure and use conditions of the flow meter.