Abstract: An apparatus includes a sensor body, a sensor configured to measure differential pressure, and first and second pressure inputs in or on the sensor body. The pressure inputs are configured to provide multiple input pressures to the sensor. Each pressure input includes a barrier diaphragm configured to move in response to pressure and an overload diaphragm configured to limit movement of the barrier diaphragm. The overload diaphragm is also configured to exert a preload force against the sensor body. The overload diaphragm of each pressure input may include multiple convolutions. Bases of the convolutions may be configured to provide the preload force, and tops of the convolutions may be separated from the sensor body by gaps. Tops of the convolutions that are non-adjacent may be configured to provide the preload force, and tops of the convolutions between the non-adjacent convolutions may be separated from the sensor body by gaps.

Abstract: An apparatus includes a sensor body and a sensor configured to measure pressure. The apparatus also includes at least one pressure input in or on the sensor body, where the at least one pressure input is configured to provide at least one input pressure to the sensor. The apparatus further includes multiple fluid passages configured to convey the at least one input pressure from the at least one pressure input to the sensor using a fill fluid. The multiple fluid passages are configured to both (i) transport the fill fluid and (ii) absorb thermal energy in a flame created by the sensor before the flame exits the sensor body. The fluid passages can include long and narrow straight passages, long and narrow curved or helical passages, and turns or bends. The fluid passages can have small cross-sections relative to their lengths.

Abstract: An apparatus includes a header containing a sensor configured to measure pressure and a sensor body connected to the header, where the sensor body and the header form a pressure vessel configured to receive an input pressure. The header is connected to the sensor body such that the input pressure received on an inner surface of the header is substantially equal to the input pressure received on an outer surface of the header. A lowest connection point of the header to the sensor body may be located at or above a highest point at which the input pressure extends into the header. A lower portion of the header may be unconnected to the sensor body and extend into an interior volume of the sensor body. The header may include a vent configured to expose the sensor to atmospheric pressure or a lower-pressure input pressure.

Abstract: An apparatus includes a header containing a sensor configured to measure pressure and a sensor body connected to the header, where the sensor body and the header form a pressure vessel configured to receive an input pressure. The header is connected to the sensor body such that the input pressure received on an inner surface of the header is substantially equal to the input pressure received on an outer surface of the header. A lowest connection point of the header to the sensor body may be located at or above a highest point at which the input pressure extends into the header. A lower portion of the header may be unconnected to the sensor body and extend into an interior volume of the sensor body. The header may include a vent configured to expose the sensor to atmospheric pressure or a lower-pressure input pressure.

Abstract: An apparatus includes a sensor body, a sensor configured to measure differential pressure, and first and second pressure inputs in or on the sensor body. The pressure inputs are configured to provide multiple input pressures to the sensor. Each pressure input includes a barrier diaphragm configured to move in response to pressure and an overload diaphragm configured to limit movement of the barrier diaphragm. The overload diaphragm is also configured to exert a preload force against the sensor body. The overload diaphragm of each pressure input may include multiple convolutions. Bases of the convolutions may be configured to provide the preload force, and tops of the convolutions may be separated from the sensor body by gaps. Tops of the convolutions that are non-adjacent may be configured to provide the preload force, and tops of the convolutions between the non-adjacent convolutions may be separated from the sensor body by gaps.

Abstract: An apparatus includes a sensor body and a sensor configured to measure differential pressure. The apparatus also includes first and second coplanar pressure inputs in or on the sensor body, where the pressure inputs are configured to provide multiple input pressures to the sensor. Each pressure input includes a barrier diaphragm configured to move in response to pressure and an overload diaphragm configured to limit movement of the barrier diaphragm. First and second fill fluid may be configured to convey the pressures from the barrier diaphragms of the pressure inputs to the sensor as first and second input pressures. Passages may be configured to transport the fill fluid between (i) gaps between the barrier diaphragms and the overload diaphragms of the pressure inputs and (ii) the sensor and gaps between the overload diaphragms and the sensor body.

Abstract: An apparatus includes a sensor body and a sensor configured to measure pressure. The apparatus also includes at least one pressure input in or on the sensor body, where the at least one pressure input is configured to provide at least one input pressure to the sensor. The apparatus further includes multiple fluid passages configured to convey the at least one input pressure from the at least one pressure input to the sensor using a fill fluid. The multiple fluid passages are configured to both (i) transport the fill fluid and (ii) absorb thermal energy in a flame created by the sensor before the flame exits the sensor body. The fluid passages can include long and narrow straight passages, long and narrow curved or helical passages, and turns or bends. The fluid passages can have small cross-sections relative to their lengths.

Abstract: A pressure sensor includes a housing with a cavity. The cavity includes a fill fluid and a compensation material. The fill fluid conveys a pressure from a process fluid through a diaphragm to a sensor. The compensation material reduces a difference of thermal expansions between the cavity and the fill fluid.

Abstract: A method and control system that monitors the high frequency or commonly referred to as the “noise” component of a measurement signal to detect plugging conditions in fluid flow systems monitored by DP-cell based sensors. This high frequency component has contributions from the process factors like disturbances, user actions and random effects like turbulence. A test statistic &thgr;(t) has been developed that monitors the proportion of variance introduced by the first two factors and the third factor. By monitoring this proportion, it is possible to detect a frozen sensor that is characterized by a dramatic reduction in the variance due to process factors over a sufficiently long detection window. The method and control system uses random sampling intervals to improve data quality. The sampling rate is also reduced by taking samples at a lower rate and then reconstructing the original signal from fewer data points.

Abstract: A method and control system that monitors the high frequency or commonly referred to as the “noise” component of a measurement signal to detect plugging conditions in fluid flow systems monitored by DP-cell based sensors. This high frequency component has contributions from the process factors like disturbances, user actions and random effects like turbulence. A test statistic &thgr;(t) has been developed that monitors the proportion of variance introduced by the first two factors and the third factor. By monitoring this proportion, it is possible to detect a frozen sensor that is characterized by a dramatic reduction in the variance due to process factors over a sufficiently long detection window. The method and control system uses random sampling intervals to improve data quality. The sampling rate is also reduced by taking samples at a lower rate and then reconstructing the original signal from fewer data points.