The pressure loss is small, the range is large, the precision is high, in the measurement of working condition volume flow is almost not affected by the fluid density, pressure, temperature, viscosity and other parameters. No movable mechanical parts, so high reliability and small maintenance. The instrument parameter can be stable for a long time. Vortex flowmeter using piezoelectric stress sensor, high reliability, can work within the -20℃~+250℃ operating temperature range. There are analog standard signals, digital pulse signal output, easy to use with computer and other digital systems, is a relatively advanced, ideal measuring instruments.