Abstract:
A method for the measurement of pressure in high temperature and high pressure processes includes the steps of providing at least a first material compound and at least a second material compound. The at least first and second compounds are mixed to form a material sample. The material sample is loaded into a device and the device and material sample are subjected to a high pressure of up to about 10 GPa and a high temperature of up to about 2000° C. to form the material sample into a solid crystalline solution. The material sample is recovered for analysis and the composition of the crystalline solid solution is measured to determine the pressure ex situ.
Abstract:
The force calculation system of the present invention is provided with: an air blowing unit for blowing air at a predetermined pressure; a flow passage for air blown from air blowing unit; a sensing unit for changing the ease of flow of air that flows through a flow passage by deforming when an external force is given; a storage unit for storing in advance the flow volume-force correspondence information showing the correspondence between the magnitude of the force received by the sensing unit and the flow volume at which air blown from air blowing unit flows through the flow passage; and a processing unit for calculating the magnitude of external force received by the sensing unit, on the basis of the flow volume of air flowing through the flow passage as measured by a flow volume meter; and the flow volume-force correspondence information stored in the storage unit.
Abstract:
In a method or field device for determining a position of an open/closed-valve positioned by a pneumatic actuating drive and movable to a completely opened open position and a closed position depending on operating requirements, during normal operation a pneumatic working chamber of the actuating drive is pneumatically influenced with an i/p converter such that the open/closed-valve moves to one of the open/closed positions and, in case of a predetermined operating condition, the i/p converter allows the working chamber to vent so that the open/closed valve automatically moves to the other one of the open/closed positions. At least one of pressure prevailing in the working chamber and pneumatic control pressure output at the i/p converter is captured continuously over time, thus obtaining a pressure change over time on the basis of which a physical operational variable of the open/closed-valve is determined.
Abstract:
The invention relates to a method for monitoring the functionality of an actuator (1) having a pneumatic drive (2), in particular for monitoring an actuator (1) for a safety valve, including a magnetic valve (4) for controlling the pneumatic drive (2), wherein the magnetic valve (4) is monitored by means of a pressure measurement and is, for this purpose, connected to a first pneumatic conduit (16) to a position controller (3) of the actuator (1) as well as to the pneumatic drive (2) to a second pneumatic conduit (17). The magnetic valve (4) is switched off and on again with a switching time (t2−t1). The switching time (t2−t1) of the magnetic valve (4) is detected at which, at the one hand, the switching time (t2−t1) is so short that the position of the actuator (1) remains essentially constant or unchanged and, on the other hand, it is, however, so long that a pressure drop (dp=P1−P2) in the first pneumatic conduit (16) in front of the magnetic valve (4) is present after switching the magnetic valve (4) on again.
Abstract:
A system and method for measuring contact pressures between two surfaces, and especially, between the body and a device resting on the body, e.g., the skin and a breathable gas mask. A deformable, resilient probe having a flow passage therein is initially placed between the two surfaces such that the flow passage is blocked. Fluid pressure within the probe is then increased until the pressure in the probe overcomes the contact pressure between the two surfaces, such that fluid begins to flow through the flow passage in the probe. The pressure at which the fluid begins to flow through the flow passage in the probe is recorded as the contact pressure between the two surfaces. Contact pressure maps created using this apparatus and method may be used to create anthropometric models of the face and other body parts.
Abstract:
Four load cells supporting a seat or part thereof provide four signals that are added to determine the weight of the seat occupant. Each load cell has two flanged springs stressed to provide preload. The two springs operate in concert to resist side forces and moments, making the load cell responsive to both compressive and tensile forces while being substantially unresponsive to lateral forces and moments tending to cause angular misalignment between input elements. A preferred load cell has a liquid filled chamber and a pressure sensor providing an electric signal indicating the pressure in the liquid, which is related to the applied force. Preferred manufacturing methods make the cost low. A seat belt tension sensor may close a switch at a predetermined seat belt tension or may measure the seat belt tension. A preferred mounting limits side forces to the load cells.
Abstract:
A weight estimation apparatus for the passenger seat of a motor vehicle, in which a single bladder substantially encompassing the seat bottom is evacuated and then inflated with a known volume of air. The average pressure in the bladder is determined to estimate the passenger weight. According to a first embodiment, the apparatus continues to monitor the average pressure, and the process is re-initiated if the average pressure changes by at least a predetermined percentage. According to a second embodiment, a bleed valve allows the pressure in the bladder to slowly escape, and the apparatus monitors the rate of change in pressure as a corresponding indication of passenger weight; in this embodiment, the process of evacuating and inflating is re-initiated if the monitored change in pressure does not correspond with the estimated weight. The sides of the bladder may be pleated to permit the bladder to expand under the weight of an occupant without stretching the bladder, and thereby affecting the average pressure. A temperature sensor may be disposed in proximity to the bladder provides a temperature signal for compensating the weight estimation for temperature variations. Also, the pressure sensor may be configured to sense the gage pressure--that is, the differential pressure between the bladder pressure and atmospheric pressure; alternatively, the pressure sensor may be configured to detect absolute pressure, and a second absolute pressure sensor responsive to atmospheric pressure may be used to compensate for changes in atmospheric pressure.
Abstract:
While a bag (1) made of a thin, soft, and less elastic material is packed with air and is positioned between contacts of soft materials, a thin tube (2) from the bag (1) is lead to the outside of the contacts, and the pressure difference with respect to atmosphere is measured, whereby the contact pressure of an elastic body can be measured. As water depth (A) (mmH.sub.2 O) is measured while the bag (1) is horizontally sank into the water, and as water temperature is changed while the water temperature is measured, the measured level can be calibrated together with thermal influence.
Abstract:
A silicon sensing cell (12) capable of sensing force and/or displacement, and particular embodiments of the sensing cell (12) for particular force and/or displacement-sensing applications. The sensing cell (12) generally includes a diaphragm (18), a silicon sensing element (28) operatively associated with the diaphragm (18) to sense strain or deflection of the diaphragm (18), a base (14) supporting the diaphragm (18) so that the base (14) and the diaphragm (18) define a recess (22), and a force-distributing member (20) within the recess (22) and contacting the diaphragm (18). The diaphragm (18) is preferably single-crystal silicon, and the sensing element (28) can be a piezoresistive, piezoelectric or capacitive element preferably formed in the diaphragm (18) using semiconductor fabrication processes. With appropriate adaptations, the sensing cell (12) can be made suitable for automotive applications such as seat occupancy sensing, brake-by-wire and acceleration-by-wire pedal systems, and media-compatible high-pressure sensing in brake, oil and transmission fluid applications.
Abstract:
Methods and apparatuses, in one aspect, for detecting and indicating loads and/or forces on tubular strings, e.g. tubing, injected into or withdrawn out of a well by an injector apparatus, the apparatus having, in one embodiment, a single piston acting on a single boot with a chamber therein having a fluid the compression of which in response to a load or a change in load is sensed to indicate the load on the apparatus; the indicator in one embodiment having a spring to add to the weight of the injector apparatus to provide a positive pre-load so that negative loads can be determined by a change in positive pressure without requiring negative pressure; and a pressure chamber device for use with such apparatuses and in such methods.