Patent classifications
G01L27/005
Sensor arrangement and method of operating a sensor arrangement
A sensor arrangement and a method of operating a sensor arrangement are disclosed. In an embodiment, a sensor arrangement includes a pressure sensor realized as a capacitive pressure sensor, a capacitance-to-digital converter, a test circuit and a switching circuit coupling the capacitance-to-digital converter and the test circuit to the pressure sensor.
Method and apparatus for damping diaphragm vibration in capacitance diaphragm gauges
A system and method mitigate the effects of these external vibrations on a capacitance diaphragm gauge by sensing the motion of the diaphragm at the first natural frequency of the diaphragm of the CDG. The presence of the natural frequency signals superimposed on the pressure signal is determined by sensing variations in the output of a sensor at or near the known natural frequency of the diaphragm and filtering that known low frequency from the output. The filtered signal is used in a feedback circuit to impose electrostatic forces on the diaphragm. The imposed electrostatic forces oppose the motion created by the external vibration to suppress the effects of the vibration on the pressure measured by the CDG.
Method and apparatus for cancelling interconnection capacitance
The present invention relates to a method for cancelling effects of changes in interconnection capacitances on capacitive sensor readings, and an apparatus configure to perform such method. The sensor readings are provided by a capacitive sensor connected with an interface circuitry. The interface circuitry has at least two interconnections comprising a sensor interconnection and a compensating interconnection. The method comprises obtaining a total sensor capacitance value from the capacitive sensor, and obtaining a total compensating interconnection capacitance value from the compensating interconnection, calculating a compensated sensor capacitance value by reducing the obtained total compensating interconnection capacitance value multiplied with a weight coefficient from the obtained total sensor capacitance value and providing at an output of the interface circuitry an electrical signal corresponding to the compensated sensor capacitance value. The weight coefficient is independent of changes of relative permittivity in the immediate environment of the capacitive sensor and its interconnections.
Load-Lock Gauge
A load lock pressure gauge comprises a housing configured to be coupled to a load lock vacuum chamber. The housing supports an absolute vacuum pressure sensor that provides instantaneous high vacuum pressure signal over a range of high vacuum pressures and a differential diaphragm pressure sensor that provides an instantaneous differential pressure signal between load lock pressure and ambient pressure. The housing further supports an absolute ambient pressure sensor. A low vacuum absolute pressure is computed from the instantaneous differential pressure signal and the instantaneous ambient pressure signal. A controller in the housing is able to recalibrate the differential diaphragm pressure sensor based on measured voltages of the sensor and a measured ambient pressure during normal operation of the pressure gauge with routine cycling of pressure in the load lock.
Pressure calibration apparatus and pressure instrument calibration information processing method
A pressure calibration apparatus and a pressure instrument calibration information processing method, belonging to the field of pressure instrument measurement and calibration. The pressure calibration apparatus comprises: a pressure calibration unit (1) externally connected to the calibrated pressure instrument (100); a main control unit (2), which is electrically connected to the pressure calibration unit (1); a communication module (3) that is electrically connected to the main control unit (2), and carries out data interaction with a remote database (300) through a network (200). The pressure calibration apparatus can be in a real-time communication connection with the remote database (300), and implements on-field real-time downloading of historical calibration data and calibration schemes of the calibrated pressure instrument (100) and real-time uploading of current calibration data.
LOCATION OF INTEREST ALTITUDE AND DETERMINING CALIBRATION POINTS
Described herein are techniques to enable a mobile device to perform multi-source estimation of an altitude for a location. A baseline altitude may be determined at ground level for a location and used to calibrate a barometric pressure sensor on the mobile device. The calibrated barometric pressure sensor can then estimate changes in altitude relative to ground level based on detected pressure differentials, allowing a relative altitude to ground to be determined. Baseline calibration for the barometric sensor calibration can be performed to determine an ambient ground-level barometric pressure.
Sensor with multiple modes or ranges
In accordance with an embodiment, a sensor includes: a signal source with a first signal source terminal and a second signal source terminal; a bridge circuit connected to the first and second signal source terminals, the bridge circuit including: a first branch including: a first reference impedance element; and a first sensor impedance element configured to transduce a magnitude to be measured into a first impedance-related parameter; and a second branch including: a second reference impedance element; and a second sensor impedance element configured to transduce the magnitude to be measured into a second sensor impedance-related parameter.
CALIBRATION SYSTEM FOR PRESSURE SENSOR
A calibration system for calibrating pressure sensor comprises communication pipe, base, inlet valve, outlet valve, pump, inlet pipe, heater and reference pressure sensor. The communication pipe has first and second openings. The base comprises chamber body and outlet being disposed at the chamber body. The inlet valve is disposed at the first opening. The chamber body is connected to the second opening so as to define a space between the inlet valve and the outlet valve. The heater is to heat a fluid in the space. The reference pressure sensor is configured to measure a pressure of the fluid. The at least one target pressure sensor is detachably mounted on the chamber body via the base so as to measure the pressure of the fluid in the space.
Process venting feature for use in sensor applications with a process fluid barrier
A pressure transmitter includes a housing and a pressure sensor having an electrical characteristic that varies with applied pressure. The pressure sensor is configured to generate a sensor signal indicative of process fluid pressure. A transmitter isolation diaphragm is configured to couple to a process barrier seal to convey pressure to the pressure sensor. A flange is coupled to the transmitter isolation diaphragm. The flange includes at least one gas pathway extending inwardly from an outer diameter of the transmitter isolation diaphragm. Electronics are coupled to the pressure sensor to receive the sensor signal and to generate an output indicative of the pressure.
PRESSURE SENSOR WITH CALIBRATION FUNCTION AND CALIBRATION METHOD THEREOF
A pressure sensor with calibration function includes a casing, a diaphragm, a sensing element, a medium, and at least one calibration element. The diaphragm is disposed on the casing, wherein the casing and the diaphragm define an accommodating space. The sensing element is disposed in the casing. The medium is filled in the accommodating space and in contact with the sensing element. The at least one calibration element is adjustably disposed at the casing and extended into the accommodating space to be in contact with the medium, wherein when the at least one calibration element is moved relative to the casing, the at least one calibration element changes the pressure applied to the medium.