Ultrasonic flow meters work on the principle Transit-time, measuring the difference of time the ultrasonic waves travel in measured liquid in the upstream and downstream direction.
The possibilities of using ultrasonic flow meters are very wide in many industries, especially in water management, energy, chemical and petrochemical industries.
The sensor of the ultrasonic flow meter is a weldment or a casting in which the ultrasonic probes are located. The sensor has dimensions according to the specific application up to a pipe size DN1200 (48"). The sensor is usually connected with flanges, manufactured in accordance with specific standards based on customer needs. According to the specific requirements for the parameters of ultrasonic flow meters, it is possible to implement single and multi-beam flow meters.
The evaluation electronics provides pulse excitation of the ultrasonic probes, measures the flying time between the ultrasonic probes and calculates of flow velocity and flow rate. The calculated flow rate is displayed and measured date can be tranfered by eletrical and communication outputs.
The electronics can be powered by AC or DC voltage or battery. The evaluation electronics is usually equipped with the keyboard, display and cable glands. The final specification of evaluation electronics depends on the type, application and customer requirements. The terminal box can be placed directly on the flow meter sensor or remotely. The remote version is mainly used where the temperature of the measured medium is higher than 70°C (158°F), or where local conditions (location and availability of the sensor) require it.