Whichever type of instrument you require, whether it’s the traditional impeller mechanism or the high accuracy electromagnetic type, Valeport can offer a solution. Configurations are available that are suitable for use in a wide variety of applications, from handheld measurements in the smallest streams, through modelling experiments in the laboratory, to self-contained instruments for navigable rivers, estuaries, ROVs and the deep ocean.
Our impeller instruments use the simple premise of measuring the speed of rotation of a helix in the water. PTFE bearings eliminate the need for specialised lubricants and the magnetic contact closure minimises the moving parts in the system – this also allows the sensor itself to be remote from the measuring electronics (ideal in deepwater applications).
The electromagnetic sensors use the Faraday Principle to measure the water speed. As a conductor (water) moves through an electromagnetic field (generated by the sensor), it generates a voltage that is measured by the sensor electrodes. Modern-day signal conditioning electronics and filtering techniques allow highly accurate measurements to be made, and there is a choice of sensor shapes and sizes to suit the application. The solid-state sensors and standard titanium/polyurethane construction provide excellent corrosion resistance and depth ratings up to 5000m.