Micromachined inclinometer based on fluid convection

This paper presents the experimental and theoretical study of an inclinometer based on heat exchange. The principle of the sensor is composed of a resistance heater placed between two detectors and suspended in a cavity filled with fluid. In this study, several fluids such as liquid or gaseous, were used. The temperature gradient and sensitivity as a function of fluid were studied by using the numerical resolution of equations of fluid dynamics with the Computational Fluid Dynamics (CFD) software Fluent V6.2. We showed that the sensitivity of the ldquoliquid sensorsrdquo is greater than ldquogas sensorsrdquo one. The experimental measurements corroborate with numerical simulation. In addition, we have demonstrated that the sensitivity of the sensor is proportional to the Rayleigh number which is characteristic of the natural convection flow.