Flow meter is an indispensable type of meter in industry. Flow meters are divided into many kinds, such as: rotameter, electromagnetic flowmeter, vortex flowmeter, turbine flowmeter and so on. There are many small types of flow meters that can be divided into each type of flow meter. For example, the rotameter can be divided into glass rotameter, metal tube float flowmeter, plastic tube float flowmeter, micro flow meter and so on.

 

       Rotameter is also called float flowmeter. The medium flows in the flowmeter pipe. From bottom to top, the buoyancy of the fluid and upward power drive the float to rise, but when it reaches an equilibrium value with the gravity of the float, this position is the flow rate. The true value.

 

      Rotameters are easy to install and are used in many industries. Low price and convenient reading are the advantages of rotameters. However, some customers have reported some failures. To summarize, there are generally three common failures.

 

       1. The measurement error of the rotameter is large: the production of the flowmeter needs to involve temperature, pressure, density and so on. Especially with changes in gas, temperature and pressure, the density of the gas will also change. At this time, if the temperature and pressure parameters given by the customer are not accurate at the beginning, the data measured by the flowmeter must be in error. For gas, temperature and pressure compensation can be considered, but it is generally used in vortex flowmeters. When purchasing a flow meter, be sure to clarify the various parameters with the flow meter manufacturer to ensure the accuracy of the flow meter in actual use.

 

        2. Rotameter pointer jitter: 1. Slight pointer jitter: generally caused by medium fluctuations. It can be overcome by increasing damping. 2. Moderate pointer jitter: generally caused by the flow of the medium. The pressure stabilization or flow stabilization device can be used to overcome or increase the gas damping of the rotameter. 3. Severe pointer jitter: Mainly due to medium pulsation, unstable air pressure, or the pressure, temperature, and flow rate of the gas operating state given by the user that do not match the actual state of the rotameter. Large differences cause the rotameter to over-range.

 

      3. The pointer of the rotameter stops to a certain position and does not move: the main reason is that the rotor of the rotameter is stuck. Generally, when the rotameter is used, the valve is opened too fast, so that the rotor quickly hits the stopper upwards, causing the stopper to deform and the rotor to be stuck. However, it is not ruled out that the rotor guide rod and the stop ring are not concentric, causing the rotor to jam. When handling, disassemble the meter, remove the deformed stopper and reshape it, and check whether it is concentric with the guide rod. If it is not concentric, correct it, then install the rotor, push the rotor by hand, and feel that the rotor is unobstructed up and down. Yes, in addition, the rotameter must be installed vertically or horizontally, and not inclined, otherwise it will easily cause the meter to jam and bring errors to the measurement.