Highly sensitive giant magnetoresistance (GMR) based ultra low differential pressure sensor

• Published in: Sensors and actuators. A. Physical. Vol. 280; pp. 125 - 131
• Main Authors: Borole, Umesh P., Subramaniam, Sasikala, Kulkarni, Ishan R., Saravanan, P., Barshilia, Harish C., Chowdhury, P.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.09.2018; Elsevier BV
• Subjects: Angle of attack; Differential pressure; Electric resistance; Electromagnetism; Giant magnetoresistance; Gradiometers; Magnetic fields; Magnetic measurement; Magnetoresistance; Magnetoresistive sensor; Magnetoresistivity; Permanent magnets; Pressure measurement; Pressure sensor; Pressure sensors; Stress concentration; Suction; Surface mounted; Wind speed; Pressure sensor; Magnetoresistive sensor; Surface mounted
• ISSN: 0924-4247; 1873-3069
• DOI: 10.1016/j.sna.2018.07.022

•Finite elemental analysis to realise the concept of the pressure sensor development.•Development of pressure sensor based on magnetoresistive technology.•Ultra low differential surface pressure measurement on a aero foil. In this study, we demonstrate a simple, cost-effective, giant magnetoresistance (GMR) based magnetic pressure sensor. The basic principle lies behind the measurement of the change in the magnetic field profile generated by the deflected diaphragm attached with a permanent magnet. This magnetic field profile change on the sensor surface was measured by highly sensitive magnetoresistive gradiometer sensor. Based on studied magnetic field distribution of a magnet, a prototype pressure sensor was designed and fabricated, which consists of a polymer diaphragm, a permanent magnet and a giant magnetoresistance based magnetic field gradient sensor. The fabricated prototype was calibrated for ultra-low differential pressure range and it shows: (i) sensitivity up to 16.67 μV/V/Pa and (ii) nonlinearity of 1.5% FS in the range of 0–300 Pa. The real time application was demonstrated where, the sensor was flush mounted on a NACA 4415 airfoil, and both the static and the dynamic suction pressures were recorded as a function of the wind velocity and also with different angle of attack (AOA). The measured pressure was found to be highly accurate while compared with existing static measurement system.