In air compressors, flow meters can be installed to measure the flow of compressed air. Different equipment has different demand for compressed air, so it is necessary to measure the air flow to ensure the normal operation of the equipment, to help the user to understand the air consumption, timely detection and solution of equipment failure problems. When the compressed air flow is abnormal, the flow meter can alarm in time to remind the user to deal with it. In the production process, compressed air is also an important source of energy. Accurate measurement of air flow can avoid energy waste, improve energy utilization and reduce production costs.