Development of a new ultrasonic liquid flowmeter for very low flow rate applicable to a thin pipe

A new ultrasonic liquid flowmeter has been developed to measure very low flow rate. This flow meter consists of small disk ultrasonic transducers and measuring pipe whose diameter is less than 1 mm. The measuring pipe passed through the ultrasonic transducer two times making the loop feature. A very low flow rate less than 1ml/min can be measured accurately and stably.