Displacement sensor

ASTM D3763, Test Methodfor iiigh-Speed Puncture Properties of Plastics Using Eoad and Displacement Sensors, Vol. 8.02, ASTM, Philadelphia, Pa., 1993. 

A most recent commercial Nano Indenter (Nano Indenter XP (MTS, 2001)) consists of three major components [66] the indenter head, an optical/atomic force microscope, and x-y-z motorized precision table for positioning and transporting the sample between the optical microscopy and indenter (Fig. 28). The load on the indenter is generated using a voice coil in permanent magnet assembly, attached to the top of the indenter column. The displacement of the indenter is measured using a three plate capacitive displacement sensor. At the bottom of the indenter rod, a three-sided... 

Mossbauer resonance of Zn to study the influence of the gravitational field on electromagnetic radiation. A Ga ZnO source (4.2 K) was used at a distance of 1 m from an enriched ZnO absorber (4.2 K). A red shift of the photons by about 5% of the width of the resonance line was observed. The corresponding shift with Fe as Mossbauer isotope would be only 0.01%. The result is in accordance with Einstein s equivalence principle. Further gravitational red shift experiments using the 93.3 keV Mossbauer resonance of Zn were performed later employing a superconducting quantum interference device-based displacement sensor to detect the tiny Doppler motion of the source [66, 67]. 

Displacement sensors are used in a very wide field of applications in research, development, quality inspection, automation, machinery and process control. Many physical parameters can be reduced to a displacement or change of distance, and can be measured with highest precision. Displacement sensors detect physical parameters like bending, deflection, deformation, diameter, eccentricity, elongation, gap, length, play, position, revolution, roundness, shift, stroke, thickness, tilt, tolerances, vibration, wear and width. 

There are two product categories of displacement sensing technology. Whenever the moving target is mechanically connected to a sensor, it is referred to as a contact displacement sensor. The physical principles adapted for contact displacement sensors are primarily ... 

If the object to be measured cannot be mechanically attached to the moving target, does not permit contact or any external force, a non-contact displacement sensor has to be used. The physical principles for non-contact displacement sensors are primarily ... 

The basis for this latest development was a displacement sensor designed by Micro-Epsilon. The sensor combines unbalance detection and measuring of the load in a single sensor module. With the information provided by the sensor, the electronic controller of the machine detects the laundry load and suggests to the user the required amount of detergent Moreover the necessary amount of water is controlled. By sensing the unbalance of the drum, the number of revolutions... 

Position/Displacement sensors can be used in active damping systems of industrial washing machines in order to compensate for vibrations coming from unbalanced drums /laundry. These can work much like a simple automotive shock absorber. 

Inductive Displacement Sensors and Linear Gaging Sensors linear variable differential transformer principle Micro-Epsilon transSENSOR... 

Draw-wire Displacement Sensors draw wire... 

The load applied to the specimen was measured by a load cell of 5 kN. The displacement of the specimen was approximately measured from the movement of the crosshead by a displacement sensor of strain gage type. The analog outputs were converted and stored in a computer as digital data. 

Fig.l also shows the schematic diagram of the instrument to measure the curvature of a substrate during thermal spray[5]. A strip-shaped substrate is fixed onto a pair of knife edges by a pair of springs and the displacement at the center of the rear surface is measured by a displacement sensor. A thermocouple is spot welded to record the thermal history. 

Depending on the application more components can be added, such as various sensors (e.g., current sensor, tool displacement sensor in gravity-feed drilling) or electrolyte supply systems. 

Many sensors use capadtors for interfacing to electronic circuits. The ability of the electronic circuit to resolve minute changes in capacitance translates into excellent sensor resolution. When used as displacement sensors, capacitive interfaces achieve resolutions down to the sub-atomic level. For example, the gyroscope described in [1] resolves displacements as small as 10-14 m. For comparison, the classical radius of an electron is 2.8 x 10 15 m and the distance between atoms in the silicon crystal is orders of magnitude larger, 2.5 x 10 10 m. The capacitance resolved by the circuit is 10-20 F, six orders-of-magnitude less than the gate capacitance of a transistor with sub-micron dimensions. 

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