Search results
Results from the WOW.Com Content Network
An accelerometer measures proper acceleration, which is the acceleration it experiences relative to freefall and is the acceleration felt by people and objects. [2] Put another way, at any point in spacetime the equivalence principle guarantees the existence of a local inertial frame, and an accelerometer measures the acceleration relative to that frame. [4]
Actigraphs have a number of different ways of accumulating the values from the accelerometer in memory. ZCM (zero crossing mode) counts the number of times the accelerometer waveform crosses 0 for each time period. PIM (proportional integral mode) measures the area under the curve, and adds that size for each time period.
Accelerometers on the surface of the Earth measure a constant 9.8 m/s^2 even when they are not accelerating (that is, when they do not undergo coordinate acceleration). This is because accelerometers measure the proper acceleration produced by the g-force exerted by the ground (gravity acting alone never produces g-force or specific force).
An accelerograph can be referred to as a strong-motion instrument or seismograph, or simply an earthquake accelerometer.They are usually constructed as a self-contained box, which previously included a paper or film recorder [1] (an analogue instrument) but now they often record directly on digital media and then the data is transmitted via the Internet.
Piezoelectric measuring devices are widely used today in the laboratory, on the production floor, and as original equipment for measuring and recording dynamic changes in mechanical variables including shock and vibration. Some accelerometers have built-in electronics to amplify the signal before transmitting it to the recording device.
An attitude and heading reference system (AHRS) consists of sensors on three axes that provide attitude information for aircraft, including roll, pitch, and yaw.These are sometimes referred to as MARG (Magnetic, Angular Rate, and Gravity) [1] sensors and consist of either solid-state or microelectromechanical systems (MEMS) gyroscopes, accelerometers and magnetometers.
An accelerometer was announced that used infrared light to measure the change in distance between two micromirrors in a Fabry–Perot cavity. The proof mass is a single silicon crystal with a mass of 10–20 mg, suspended from the first mirror using flexible 1.5 μm-thick silicon nitride (Si 3 N 4) beams. The suspension allows the proof mass to ...
Accelerometer — an accelerometer can measure any motion that is used in combination with the other mentioned components, providing motion and location sensing heart rate data via an algorithm 4. Algorithms — an algorithm is formed from the processor and the accelerometer into biometric data .