Abstract: A self-calibrating pressure sensor system may measure the pressure of a gas or liquid. The system may include a pressure sensor, a reference sensor, and a drift compensation system. The pressure sensor may include a pressure-sensing flexible diaphragm with one side exposed to the gas or liquid and another side forming a wall of a sealed chamber. The reference sensor may include a reference flexible diaphragm that has two sides that are both within or exposed to the same sealed chamber. The drift compensation system may produce information that is indicative of the pressure of the gas or liquid based on the signal from the pressure sensor, and compensate for drift in this signal based on changes in the signal from the reference sensor. The pressure-sensing flexible diaphragm and the reference flexible diaphragm may be made at substantially the same time by depositing or growing a single layer of material in a single continuous step.

Abstract: A system for monitoring a sensor includes a GUI (Graphical User Interface) such as a WebPage embedded in the sensor. The GUI is configured to display information relating to the sensor from a user computer connectable to the sensor via an Ethernet connection and having an internet web browser for accessing the WebPage of the sensor. A computer-readable medium is embedded within the sensor and has stored therein computer-usable instructions for a processor. These instructions, when executed by the processor, cause the processor to generate the GUI.

Abstract: A heater is disclosed for use with pressure transducers. The disclosed heater includes a first heating element and a second heating element. The first heating element is characterized by a first electrical resistance. The second heating element is characterized by a second electrical resistance. In preferred embodiments, the first electrical resistance is different than the second electrical resistance. The disclosed heater can be used to accurately heat a pressure transducer to at least four different operating temperatures by selectively (a) connecting the first heating element to the transducer temperature control circuitry, (b) connecting the second heating element to the transducer temperature control circuitry, (c) connecting the first and second heating elements in series with the transducer temperature control circuitry, or (d) connecting the first and second heating elements in parallel with the transducer temperature control circuitry.

Abstract: A compensated sensor includes a sensor, a relatively fast feedthrough path, and a relatively slow compensation path. The relatively fast feedthrough path includes a summer and output circuitry, such as a summing amplifier. The relatively slow compensation path includes circuitry that produces one or more correction factors for such sensor deficiencies as temperature dependency, or nonlinearity effects, for example. These one or more correction factors are fed to the summer for summing with the uncompensated sensor output. Additionally, the output of the output circuitry (e.g., summing amplifier), is fed back to the compensation circuitry where it is compared to a compensated sensor output developed by the compensation circuitry. The difference between the compensated sensor signal developed in the compensation circuitry and the output signal fed back to the compensation circuitry is also provided to the summer for summing with the one or more correction factors and the uncompensated sensor output.

Abstract: A compensated sensor includes a sensor, a relatively fast feedthrough path, and a relatively slow compensation path. The relatively fast feedthrough path includes a summer and output circuitry, such as a summing amplifier. The relatively slow compensation path includes circuitry that produces one or more correction factors for such sensor deficiencies as temperature dependency, or nonlinearity effects, for example. These one or more correction factors are fed to the summer for summing with the uncompensated sensor output. Additionally, the output of the output circuitry (e.g., summing amplifier), is fed back to the compensation circuitry where it is compared to a compensated sensor output developed by the compensation circuitry. The difference between the compensated sensor signal developed in the compensation circuitry and the output signal fed back to the compensation circuitry is also provided to the summer for summing with the one or more correction factors and the uncompensated sensor output.

Abstract: A capacitive pressure transducer including a heater shell, a capacitive pressure sensor, an electronics assembly and a thermal barrier is presented. The sensor and the electronics assembly are disposed in the heater shell. The thermal barrier is also disposed in the heater shell and is disposed between the sensor and electronics assembly.

Abstract: A method is disclosed for providing transient temperature compensation in a pressure transducer. The transducer includes a capacitive pressure sensor, the pressure sensor including a diaphragm, at least part of the diaphragm moving in response to changes in a pressure. The transducer may further include an electronic circuit which generates an uncompensated output signal representative of the pressure. The disclosed method generates a compensated output signal according to a function of the uncompensated output signal and a difference between a temperature of the pressure sensor and a temperature of the ambient environment.

Abstract: A pressure transducer has an output characterized by two or more slopes. A pressure transducer generates an first output signal that may be linearly proportional to the sensed pressure. The pressure transducer includes an electrical circuit that shapes the first output signal to produce a shaped output signal that according to a first function of the first output signal when the first output signal is less than the first value and according to a second function of the first output signal when the first output signal is greater than a second value. Preferably, the shaped output signal is a dual slope signal such that the shaped output signal has a first linear portion characterized by a first slope and a second linear portion characterized by a second slope. The two linear portions of the shaped output signal may intersect at a knee point which corresponds to a pressure between two preferred desired pressure ranges.

Abstract: A capacitive pressure transducer is disclosed. The disclosed transducer includes a heater shell, a capacitive pressure sensor, an electronics assembly, and a thermal barrier. The sensor and electronics assembly are disposed in the heater shell. The thermal barrier is also disposed in the heater shell and is disposed between the sensor and electronics assembly.

Abstract: A capacitive pressure sensor includes a chamber coupled to a region whose pressure is to be determined. The sensor includes a conductive flexible diaphragm and a pair of electrodes, each defining a capacitance with the diaphragm. Variations in pressure in the chamber cause deflection of the diaphragm which in turn causes variation in the capacitances. A processing circuit applies an excitation signal to the capacitances and couples the capacitances to inductive elements. A current through the inductive elements is detected to determine the difference in the sensor capacitances and, therefore, the deflection of the diaphragm and the pressure in the chamber.