UAT ISC / A&R 19 UAT ISC A&R 19 | Page 29

4.2.2 Speed sensors Speed sensors perform measurement by taking consecutive position measurements at constant time intervals, calculating the time change ratio of position values, or determining it directly based on different principles. 1. All position sensors 2. Tachometer 3. Hall effect sensor 4.2.3 Acceleration sensors They are designed to perform a measurement of acceleration or vibration. These provide an electrical signal according to the physical variation they measure, in this case the physical variation is acceleration or vibration. It is noted here that the speeds and accelerations measured by the use of position sensors require differentiations. Usually, this is not desirable, since the noise in the measured data, if any, will be amplified. Alternatively, it is recommended to use integrators to obtain the speed from acceleration and therefore positions. Integrators tend to suppress noise.