Air data sensor solves problem for the Met Office
Aerospace Engineering researchers have developed an innovative air data sensor – believed to be the smallest, most accurate and most powerful of its type in existence – for the Met Office.
The sensor, which is just 11mm in diameter, is due to be mounted on board the FAAM (Facility for Airborne Atmospheric Measurements) aircraft, a facility run by the Met Office through the National Centre for Atmospheric Science (NCAS).
Capable of measuring both the speed and direction of air, the sensor was developed by the Surrey Fluid Sensor Development Initiative, a programme led by Dr David Birch of the Department of Mechanical Engineering Sciences. The researchers were approached by the Met Office which required an air sensor of very small dimensions to fit the space restrictions of the FAAM aircraft.
Dr Birch explained, “The instrument currently available to fulfil this function was too large to be installed where it was needed: the whole unit needed to fit in a space roughly the size of a tea cup. Drawing on our expertise in developing high precision, pressure-based velocity probes, we were able to create a sensor that not only fits this small space with plenty of room to spare, but is also packed with additional sensing technology and offers very high accuracy.”
As well as being equipped with a seven-hole velocity probe (which can measure air flow with high accuracy), the unit also includes sensors that measure humidity, air temperature, case temperature and altitude. In addition, a de-icing heater was built into the probe, as was an orientation sensor to automatically correct misalignment. Thanks to internal heaters, the sensor can be used in temperatures as low as -70°C (the conventional electronics on board would otherwise not be able to function below -40°C).
Dr Birch commented, “Although the sensor was originally designed to help calibrate other aircraft sensors, because of its size and capabilities, it is now being assessed for integration into other FAAM aircraft systems. In addition, a project is currently being planned in collaboration with researchers at the University of Reading to mount the probe on a remote-control toy aeroplane, and use this to measure the atmospheric boundary layer in areas where conventional field measurement techniques cannot be used. The sensor has also attracted the interest from the motorsport sector as well as other industrial partners.”