Endress+Hauser Micropilot FMR5x radar level instruments

The Micropilot FMR5x family of non-contact level measurement instruments now offer multi-echo tracking, which allows the instruments to remain accurate when a tank with obstacles is being filled and emptied.

The traditional disadvantage relating to radar measurement has always been the need to ‘map out’ obstacles in a tank such as heating coils or agitators that provide their own echo response and may be mistaken for the actual process level. This is achieved by evaluating the echo response of an empty tank, identifying the response that relates to the bottom of the tank and then recording a static suppression ‘map’ over the echo responses caused by these obstacles. Then, only the signals that range above the map will be evaluated, the obstacles will be ignored.

When a tank is being filled or emptied, however, and the level reaches the obstacle, it too can range below the suppression map, meaning that the level signal is also ignored, causing jumping and erroneous level measurements.

Multi-echo tracking helps alleviate this problem by independently marking all measured signals - not only the level signal. It is a self-learning feature that follows the marked signals at all times and is constantly building a history of their behaviour.

Multiple echoes are identified in the evaluation both above the level surface and below the level surface in oil-based media. This parallel evaluation adds security on the measurement determination as direct and indirect techniques are employed to derive the level.