470results about How to "Accurate pressure" patented technology

A method for making a pressure sensor by providing a wafer including a base silicon layer, a buried sacrificial layer, and a top silicon layer. The top silicon layer is arranged over the buried sacrificial layer and the buried sacrificial layer is arranged over the base silicon layer. Etching vents through the top silicon layer to the buried sacrificial layer and removing a portion of the buried sacrificial layer. Depositing silicon to seal the vents and arranging a strain gauge or a capacitance contact on the wafer. A method for making a pressure sensor including providing a bulk wafer and depositing a sacrificial layer on the bulk wafer. Depositing silicon on the sacrificial layer and the bulk wafer to form an encapsulation layer. Etching vents through the encapsulation layer to the sacrificial layer and removing the sacrificial layer. Closing the vents with a silicon deposition and arranging a strain gauge or a capacitance contact on the encapsulation layer. A pressure sensing device including a substrate, an encapsulation layer with vents, and voids between the substrate and the encapsulation layer. A portion of the encapsulation layer above the voids forms a membrane and deposited silicon plugs fill the vents. A strain gauge or a top capacitive contact arranged on the membrane.

A tire inflation system includes an air supply source in selective fluid communication with a tire via a pneumatic conduit. A method of inflating the system includes providing a tire pressure retention valve in the pneumatic conduit adjacent to the tire. An inflation pressure of the tire is determined with a step-up procedure, in which air bursts are communicated from the air supply source to a portion of the pneumatic conduit between the air supply source and the tire pressure retention valve. The volume of at least one selected communicated air burst is related to a volume of a section of the conduit. The tire is inflated with an extended-pulse procedure, in which extended bursts of air are communicated from the air supply source to the tire. A shut-down sequence is performed once a predetermined target inflation pressure in the tire is reached.

Methods and systems are described for drilling a well while distinguishing circulated gas or air from pumps-off gas in a drilling fluid at downhole pressure and temperature. A well is drilled with a drilling fluid, drill string, and drill bit. Drilling fluid is pumped through the drill string, drill bit, and into an annulus between the drill string and a wellbore. The drill string comprises one or more sensors sensing a parameter indicative of circulated gas or air in the drilling fluid flowing through the drill string, one or more sensors being behind and near the drill bit. The sensors measuring gas in the drill string may be at the same level as gas detectors in the annulus. The measurements are communicated to a human-readable interface at the surface, allowing an operator to determine if pressure of the wellbore fluid is greater than formation fluid pressure.

The invention relates to the technical field of metallographic phase grinding, in particular to a metallographic phase grinding sample pressure adjusting device and a metallographic phase grinding and polishing device and method. The metallographic phase grinding sample pressure adjusting device comprises a fixed rod, a rotary connection rod and a sample clamping mechanism which are all sequentially connected; the sample clamping mechanism comprises an adjusting sleeve, a pin shaft arranged in the adjusting sleeve, a fastener installed at the upper end of the pin shaft, a spring arranged on the pin shaft in a sleeving manner and pressed in the adjusting sleeve through the pin shaft, and a sample clamping sleeve detachably installed at the lower end of the pin shaft and used for clamping a metallographic phase sample. The metallographic phase grinding and polishing device comprises the metallographic phase grinding sample pressure adjusting device, a cushion plate, a grinding and polishing disk and a motor. During grinding and polishing, firstly, pressure is preset, and then by adjusting the fastener of the pin shaft to be connected with the adjusting sleeve, the pressure is loaded onto the metallographic phase sample. According to the metallographic phase grinding sample pressure adjusting device and the metallographic phase grinding and polishing device and method, one or more metallographic phase samples can be pre-ground and polished on the same equipment, and pressure acting on the samples is adjustable and can be automatically released.

A system and a method for circuit compliance compensated pressure control in a patient respiratory ventilation system, having a pressure regulated feedback servo control loop, a pressure-regulated volume controller, and a patient volume observer. The patient volume observer is operative to estimate a patient volume, that is, the volume actually delivered to the patient by accounting for volume deviation or loss caused by patient circuit leakage and valve dynamics. Based on the difference between the estimated patient volume and a set tidal volume, the pressure-regulated volume controller is operative to generate and update a circuit compliance pressure compensation factor. The pressure regulated feedback servo control loop is operative to modulate the peak airway pressure based on the circuit compliance pressure compensation factor, so as to achieve the set tidal volume while maintaining a constant inspiratory time and a constant I:E ratio.

A direct acting pressure regulator controls the flow of a gas from a high pressure source to a low pressure device. Gas is delivered from the regulator at a predetermined outlet pressure. The regulator includes a body having a high pressure inlet and defining a seat. A bonnet is engageable with the body to define a piston chamber within the body and the bonnet. The bonnet has a regulated gas outlet. A piston is disposed within the piston chamber and defines a gap between the piston and a wall defining the chamber. The piston is movable between an open regulator condition and a closed regulator condition. The piston includes a plug having a sealing surface engageable with the seat and movable toward the seat to the closed regulator condition and away from the seat to the open regulator condition. The plug includes axially disposed openings therein for communicating gas from around the plug to a central longitudinal bore in the piston. The piston has an impingement surface in flow communication with the central bore such that gas pressure on the impingement surface exerts a force on the piston to move the piston to the closed regulator condition. A spring urges the piston to the open regulator condition.

An apparatus for determining intraocular pressure includes a transducer assembly containing an applanation tonometer for the determination of a cornea applanation pressure and an ultrasonic pachymeter to determine the thickness of the cornea at the site of applanation. The assembly has a tip end which includes an applanation surface and an ultrasonic coupler surface, and an end cap membrane holder is adapted to fit over the tip end of the transducer assembly and hold a thin film membrane stretched over the applanation and ultrasonic coupler surfaces. The transducer assembly also has a detector for detecting the presence or absence of the end cap membrane holder, the detector may generate a signal to disable movement of the transducer assembly if the end cap is not detected.