In the high-efficiency and long-term operation of the electromagnetic flowmeter, there will inevitably be problems that should not occur. For example, if there are bubbles in the electromagnetic flowmeter tube, it will affect the measurement. Today we will focus on how to solve the problem of the gas soup bag
To solve this problem, we must first learn to find the problem. How bubbles are formedWe all know that the electromagnetic flowmeter is a linear measurement principle, and we are most afraid of bubbles in the measured medium. The formation of bubble-like gas in the measured medium can be roughly divided into two categories: one is inhaled from the outside, and the other is the transformation of gas (air) dissolved in the liquid into free bubbles. There are generally some small bubbles in electromagnetic flowmeters. When these small bubbles are evenly dispersed around, it will not have much impact on our measurement results. When there are large bubbles or small bubbles in the liquid, it will cover the entire electrode when passing through the electrode, causing the flow signal input circuit to open instantly, causing the output signal to jitter1. Other methods in the work of electromagnetic flowmeter, How can we see that the measurement accuracy is related to air bubblesThe simplest identification method is to immediately cut off the excitation circuit current of the magnetic field when a shock is encountered. If the electromagnetic flowmeter still shows unstable at this time, a large part of it may be due to the existence of air bubbles2. The correct solutionIf a problem is found, there is always a solution. As a user, we should do the right thing to solve the problem that if the measured medium contains air, if it is determined that it is caused by the location of the equipment, such as the electromagnetic flowmeter is installed at the high point of the piping system, the electromagnetic flowmeter is due to trapped gas. Or, the most effective and convenient method is to change the position of the device or use a U-shaped pipe device at the lowest point of the pipeline. If the device has a large diameter or the location is not easy to change, we recommend installing a gas bag and exhaust valve upstream of the flowmeter. For example, a large-caliber electromagnetic flowmeter will cause 20-50% display jitter due to air bubbles. But after installing the exhaust device, the measurement result is normal againThe above is the solution to the formation of electromagnetic flowmeter bubbles. We hope that users will pay more attention to observation, learn more, and summarize more. Similar problems can be solved by themselves.
Post time: 21-09-21