Three axis accelerometer

A monolithic three-axis accelerometer with three independent capacitive readout circuits on a single chip is described elsewhere [7] (Fig. 6.1.14). The circuit is similar to Fig. 6.1.10 and achieves 0.085 aF/v/Hz resolution with 100 fF sense capacitors. The noise is actually dominated by Brownian noise in the sensor itself, as tests in vacuum demonstrate. The actual capacitance resolution is therefore somewhat better than stated. This circuit uses correlated double sampling (CDS) for biasing and to reject flicker noise. 

Physical activity was measured with a three-axis accelerometer that allows interpretation of its irtfluence on psychojitysiological measures. 

The apparatus was built by the Marshall Space Flight Center (MSFC). It provided three levels of containment for two samples per flight, rapid ignition of the fronts and video. A three-axis accelerometer measured acceleration levels to 0.001 g, and the values can be seen in the images. A negative value indicates "normal" acceleration downward. For example, during the high g pull-out-, the middle accelerometer (2) would read - 1.6 g. 

The heart rate can be measured by an ECG, and the posture and activity level can be measured by a three-axis accelerometer. In designing heart sensors, good contact with the skin is es sential, and interference with the working environment should be as minimum as possible. The electrodes for measuring heart rate could be textile electrodes based on electrical conductive stainless steel yams integrated into an iimer garment. The electrodes can be knitted or woven in a double-face fabric so that the outer part of the electrodes does not contain any conductive yam and insulates the electrodes from the outside environment (Sahin et al., 2005). 

The Amputees Activity Monitor (AAM) shown in Figure 1 was developed as a low-cosf lightweight, user friendly monitor which require no maintenance, can be inserted into the pylon of the prosthesis and possessed big memory capacity to keep long term ambulation raw data. It can detect the steps count and the pattern of the ambulatory function of the amputee with their prosthesis. It consist of a switch, a three axis accelerometer as sensor, a powerful in function yet low power consumption microconfioller and a... 

Dixon-Warren, S. The evolution of compact three axis accelerometers. MEMS Industry Group, MEMSblog (2010)... 

Use a spreadsheet for a three single-axis accelerometer system mounted in a steering tool or a MWD tool and compute the output current values for each accelerometer in the following cases ... 

Studies of deformations of an ice cover, its failure, natural ridging and rafting are of vital importance to ice forecasting, navigation and the safety of offshore structures. Waves as a mechanism of transfer of deformation energy play a part on the local scale and mesoscale. In this paper, we discuss the spectral structure of cyclic deformations of the ice floe. We mainly relied on the Sea Ice Mechanics Initiative (SIMI) field experiment, the Beaufort Sea, 1993-94. Of special interest were the data from the West FallWinter camp (75°N, 142°W ) set up on a 2.1 m thick multi-year ice floe. Tilt-meters, BP-Delta strainmeters and three-axis inertial accelerometers were applied in keeping the record (Fig 1). 

In the event of an earthquake occurring at the site, two peak accelerometers are provided to enable post-event decision making. The maximum local acceleration in each of the three axis is recorded, and provides indication of the magnitude of the event. 

For measurement ranges from 0 to 180°, three accelerometers mounted orthogonally must be used as shown in Figure 4-224. The x and y accelerometers are mounted with their sensitive axis perpendicular to the tool axis. The z accelerometer is mounted with its sensitive axis lined up with the tool axis. 

The wireless wearable accelerometer system utilized three (3) MMA7260QT Freescale Tri-Axial Accelerometers attached to the left knee, pelvis, and right knee. The accelerometer subsystem records the tri-axis acceleration of the... 

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