Transonic "HT110 Bypass Flowmeter" system is a non-invasive volumetric flow measuring instrument for fluid dynamic loops with an accuracy of ±10%. Flow rate is measured continuously and bidirectionally by means of ultrasonic clamp-on probes by the difference in the transit time of the sound waves inside the pipes. This measuring system guarantees the separation between the fluid and the probes, maintains the integrity of the tubes and allows the use of probes of different gauges.