brief introduction: Introduction:Flow sensors are electromechanical devices used to measure the rate of fluid flow. Fluids can be air, gas, liquid or energy. They are used in applications that require bulk fluid movement analysis including: utilities monitoring (gas and water meters), HVAC systems, fuel and lubricant flow, cooling systems, printer toner monitoring, chemical flow monitoring and irrigation control. Technologies flow sensors employ includes: mechanical, pressure, optical, Coriolis force, ultrasonic fl