Abstract:
A two-wire process variable transmitter for use in an industrial process includes a process variable sensor configured to sense a process variable of a process fluid of the industrial process. Output circuitry provides an output on a two-wire process control loop which is related to the sensed process variable. Terminal voltage measurement circuitry measures a voltage at terminals of the process variable transmitter. The terminal voltage is a voltage measured across an electrical connection of the two-wire process variable transmitter to the two-wire process control loop. A microprocessor performs loop diagnostics on the two-wire process control loop based upon a loop current and the measured terminal voltage. The microprocessor determines coefficients of a polynomial equation which relates loop current and terminal voltage during normal operation of the two-wire process variable transmitter and performs subsequent diagnostics based upon the coefficients of the polynomial.
Abstract:
A process fluid pressure transmitter is provided. The process fluid pressure transmitter includes a pressure sensor having an electrical characteristic that changes in response to a deformation of the pressure sensor in response to pressure. Measurement circuitry is coupled to the pressure sensor and is configured to provide an indication of the electrical characteristic. An isolation diaphragm is configured to contact the process fluid and deform in response to process fluid pressure. A substantially incompressible fill fluid fluidically couples the isolation diaphragm to the pressure sensor. An overpressure compliant structure is coupled to the fill fluid and is configured to be substantially rigid at pressures below a selected threshold, but to deform in response to pressure above the selected threshold.
Abstract:
A terminal feedthrough is provided. The terminal feedthrough includes a terminal pin insert having a pair of ends. A polymeric body having an externally threaded region is disposed about the terminal pin insert to form an interface with the terminal pin insert. At least one of threads of the externally threaded region and a cylindrical pin interface is configured to provide a flame-quenching pathway.
Abstract:
A seal board includes a circuit board with vias, conductor pins, and solder joints. The solder joints connect and seal each conductor pin to a single via, such that each conductor pin extends through the via and extends from a first side of the circuit board and a second side of the circuit board. The seal board is mounted to cover an opening in a bulkhead that separates a first compartment (such as a terminal block compartment) from a second compartment (such as an electronics or feature board compartment). The seal board provides electrical paths between the compartments while protecting components within one of the compartments from the surrounding environment.
Abstract:
A system for measuring concentration of water vapor in a gas includes a pressure sensor configured to sense a static pressure of the gas and a differential pressure sensor configured to sense a differential pressure. A temperature sensor senses a temperature of the gas. Circuitry estimates determines a concentration of water vapor in the gas based upon the measured pressures and temperature.
Abstract:
A system for detecting when a plunger reaches a bottom of a well includes a pressure sensor configured to measure a pressure of the well and provide a measured pressure output. Derivative calculation circuitry calculates a derivative of the measured pressure output. Detection circuitry detects when the plunger reaches the bottom of the well based upon the calculated derivative.
Abstract:
A process variable indicator is provided. The process variable indicator includes a process variable sensor having an electrical characteristic that varies with the process variable. Measurement circuitry is coupled to the process variable sensor and is configured to provide an indication relative to the electrical characteristic. A processor is coupled to the measurement circuitry and is configured to compute a process variable based on the indication and determine, among a plurality of ranges, which range the process variable is within. The processor generates a local visual output based on the process variable and the determined range. A method of visually indicating a process variable is also provided.
Abstract:
A modular, intrinsically-safe power module assembly is provided. The assembly includes a rigid conduit adapter configured to mount to a conduit of a field device. A housing, having an interior, is operably coupled to the rigid conduit adapter and is physically supported by the rigid conduit adapter. At least one non-rechargeable battery is disposed within the housing. Intrinsic safety circuitry is coupled to the at least one non-rechargeable battery, and is coupled to a connector that mates with a cooperative connector in the rigid conduit adapter.
Abstract:
An infrared sensor includes a thermopile connected in series with an ambient temperature compensation resistance temperature detector (RTD) and four electrical leads. The thermopile produces a voltage as a function of temperature of a point of interest, while the RTD varies in resistance as a function of ambient temperature. Two of the leads deliver current to energize the RTD. The other two leads are used for sensing voltages produced by the thermopile and the RTD.
Abstract:
A remote seal connection includes an outer sleeve, configured to be inserted through a penetration in a wall and having an outer surface. A capillary is within the outer sleeve and carries a fluid configured to communicate a pressure from a remote seal to a pressure transmitter. A space is provided about the capillary and is positioned between the capillary and the outer sleeve.