The DTT series transducers are non-invasive, clamp-on devices that are placed on the outside of a pipe. Proprietary circuitry allows this product to be used on both metal and plastic pipes containing relatively clean liquids as well as those with suspended solids or entrained gases. Models are available for general purpose, submersible or hazardous area applications.
Operating Principle
Each transducer utilizes a piezoelectric crystal to transmit ultrasound through a pipe wall and into a flowing liquid. The ultrasonic signal is reflected from suspended solids or entrained gases drawn out of solution by hydraulic disturbances such as a 90° elbow. (This unit can measure the flow rate of clean liquids by mounting the transducers 1 to 3 pipe diameters downstream of the 90° elbow.) A second transducer receives the reflected sound and the TFXL series meter’s circuitry compares the transmitted and received frequencies. If the liquid is moving, a frequency (phase/Doppler) shift occurs which is proportional to fluid velocity.
