| Patent Number |
Title Of Patent |
Date Issued |
| 5672975 |
Two-wire level transmitter |
September 30, 1997 |
| A level transmitter for use in a process application measures height of a product in a tank. The level transmitter includes a microwave antenna directed into the tank. A low power microwave source sends a microwave signal through the microwave antenna. A low power microwave receiver |
| 5670722 |
Mounting assembly for a pressure transmitter |
September 23, 1997 |
| The present invention relates to a mounting assembly for a pressure sensor in a pressure transmitter. The mounting assembly includes a header having a cavity opening to a first surface. The cavity is defined by an inner endwall and an inner sidewall. A support is joined to the inner endw |
| 5669713 |
Calibration of process control temperature transmitter |
September 23, 1997 |
| A transmitter in a process control loop measures temperature. A calibrator includes a known calibration element which is connected to the transmitter. Software in the transmitter compares a measured value of the calibration element with the actual value of the calibration element and |
| 5668322 |
Apparatus for coupling a transmitter to process fluid having a sensor extension selectively posi |
September 16, 1997 |
| A transmitter of the type used in the process control industry includes a sensor for sensing a process variable and a transmitter body having a sensor coupling. A sensor extension couples to the sensor coupling and includes a sensor coupling face. A first flange interface has a process |
| 5665899 |
Pressure sensor diagnostics in a process transmitter |
September 9, 1997 |
| A transmitter in a process control system includes diagnostic circuitry for determining condition of a pressure sensor. The pressure sensor includes a pressure responsive structure and a capacitor coupled to the pressure responsive structure whereby capacitance of the capacitor varies in |
| 5650777 |
Conversion circuit for process control system |
July 22, 1997 |
| Conversion circuitry for use in a process control system is adapted for coupling to a primary process control loop. Digital receiver circuitry in the conversion circuitry receives a digital signal transmitted over the primary process control loop from a field transmitter and responsively |
| 5642301 |
Transmitter with improved compensation |
June 24, 1997 |
| A circuit for compensating variables in a measurement transmitter. Within the transmitter, a sensor senses a primary process variable such as differential pressure and a converter digitizes the sensed process variable. The sensor senses pressures within a span of pressures values. A |
| 5639970 |
Current selection circuitry for magnetic flowmeter |
June 17, 1997 |
| A magnetic flowmeter system provides a volumetric flow rate output and includes flowmeter electronics for coupling to a flowtube assembly. The flowtube assembly includes a coil which receives a magnetic field producing coil current from a supply circuit in the flowmeter electronics. |
| 5637802 |
Capacitive pressure sensor for a pressure transmitted where electric field emanates substantiall |
June 10, 1997 |
| A transmitter in a process control system transmits a pressure over a process control loop. The transmitter includes I/O circuitry, compensation circuitry and an absolute pressure sensor. The I/O circuitry transmits information over the process control loop. Compensation circuitry receiv |
| 5632632 |
Flowmeter alignment device |
May 27, 1997 |
| A flowmeter alignment device comprises an alignment ring affixed to an end of a flowmeter flowtube and having spring fingers to engage the circumference of a pipe flange raised face. In another embodiment a flowmeter alignment device comprises a semicircular or other arcuate body aff |
| 5621406 |
System for calibrating analog-to-digital converter |
April 15, 1997 |
| A calibrating system calibrates an analog-to-digital converter which has an integrator and first and second reference current sources. A quantity of charge is accumulated in the integrator. The quantity of charge is removed from the integrator by applying the first and second reference c |
| 5610552 |
Isolation circuitry for transmitter electronics in process control system |
March 11, 1997 |
| A transmitter in a process control system includes isolation circuitry which isolates transmitter electronics from a sensor bridge circuit. The isolation circuitry includes high impedance isolators in series with high impedance buffers to electronically isolate the transmitter electronic |
| 5606513 |
Transmitter having input for receiving a process variable from a remote sensor |
February 25, 1997 |
| A two-wire transmitter senses a pressure using an internal pressure sensor. The transmitter includes an input for receiving a process variable from a remote sensor which is separated from the transmitter. Circuitry in the transmitters transmits information on a two-wire process control l |
| 5585777 |
Transmitter with electrical circuitry for inhibiting discharge of stored energy |
December 17, 1996 |
| A transmitter coupled to a control loop which carries a loop current senses a process variable which is transmitted over the loop. Circuitry in the transmitter presents an effective capacitance C.sub.eff to the control loop. The transmitter includes an isolation network coupled between t |
| 5573032 |
Valve positioner with pressure feedback, dynamic correction and diagnostics |
November 12, 1996 |
| In this invention, a valve positioner receives a setpoint from a master and provides a control pressure to a valve actuator for controlling a valve. A sensing circuit in the positioner senses the position of the valve and the control pressure, and a control circuit in the positioner uses |
| 5563587 |
Current cancellation circuit |
October 8, 1996 |
| A transmitter includes a sensor for sensing a primary process variable representative of a process, and providing a sensor output current. An integrator in the transmitter integrates the sensor output current. The integrator has an amplifier on an integrated circuit and an off-chip c |
| 5558115 |
Valve positioner with pressure feedback, dynamic correction and diagnostics |
September 24, 1996 |
| In this invention, a valve positioner receives a setpoint from a master and provides a control pressure to a valve actuator for controlling a valve. A sensing circuit in the positioner senses the position of the valve and the control pressure, and a control circuit in the positioner uses |
| 5549137 |
Valve positioner with pressure feedback, dynamic correction and diagnostics |
August 27, 1996 |
| In this invention, a valve positioner receives a setpoint from a master and provides a control pressure to a valve actuator for controlling a valve. A sensing circuit in the positioner senses the position of the valve and the control pressure, and a control circuit in the positioner uses |
| 5546804 |
Transmitter with moisture draining housing and improved method of mounting RFI filters |
August 20, 1996 |
| A transmitter transmitting a sensed process variable over a conductor includes a cylindrical housing having a terminal compartment and an electronics compartment separated by a bulkhead. The terminal compartment used for conductor connection is subject to moisture accumulation. An ac |
| 5535243 |
Power supply for field mounted transmitter |
July 9, 1996 |
| A field mounted transmitter for use in a two-wire process control loop includes a sensor, measurement circuitry and a power supply. The sensor senses a process variable of a process which is transmitted over the control loop by the measurement circuitry. The power supply is powered by |
| 5530639 |
Bridge pulse controlled constant current driver for magnetic flowmeter |
June 25, 1996 |
| A magnetic flowmeter system provides a volumetric flow rate output and has a coil receiving a magnetic field producing coil current from the current supply circuitry. The current supply circuitry includes an H-bridge transistor circuit having first and second switches which couple one of |
| 5524492 |
Pressure transmitter isolation diaphragm |
June 11, 1996 |
| A transmitter provides an output indicative of pressure of process fluid. The transmitter has a first body with a passageway filled with isolation fluid extending from a first port to a pressure sensor. A second body has an inlet for receiving process fluid and a second port. An isolatio |
| 5520054 |
Increased wall thickness for robust bond for micromachined sensor |
May 28, 1996 |
| A micromachined device is described receiving a pressurizable fluid has a plurality of layers bonded together along at least one bond interface, the bond interface having a terminus bordering the pressurizable fluid. In a vicinity of at least one bond interface at least one layer has a s |
| 5515732 |
Capacitive pressure sensor and reference with stress isolating pedestal |
May 14, 1996 |
| A pedestal mount capacitive pressure sensor (10) is supported in a housing (11) and used to sense fluid pressures to provide air pressure data relating to the performance of air vehicles. The capacitive sensor uses a thick base plate (40) on which a diaphragm (48) is mounted. A capacitiv |
| 5502380 |
Analog weighted binary absolute position encoder including an array of sense resistors each havi |
March 26, 1996 |
| A magnet mounted on a moving stem or rotary member of a valve generates magnetic flux over part of a stationary member of the valve which has an uniquely patterned set of magnetoresistive sense resistors and three reference resistors (the sensor) disposed thereon. The distance between |
| 5498079 |
Temperature transmitter |
March 12, 1996 |
| A temperature transmitter includes a temperature probe, such as an RTD or thermocouple, and a transmitter housing. Electrical circuitry in the transmitter housing is adapted for coupling to the temperature probe and providing an output related to a sensed temperature. The temperature |
| 5495769 |
Multivariable transmitter |
March 5, 1996 |
| In this invention, a multivariable transmitter providing an output representative of mass flow has a dual microprocessor structure. The first microprocessor compensates digitized process variables and the second microprocessor computes the mass flow as well as arbitrating communicati |
| 5495768 |
Pressure isolator assembly for sanitary processing |
March 5, 1996 |
| An isolator diaphragm is formed and connected to a support member so it will withstand periodic high pressure cleaning. Such periodic cleaning includes use of heated, concentrated cleaning solutions flowing under high pressure from a nozzle which moves rapidly over segments of an exposed |
| 5485400 |
Field-mounted control unit |
January 16, 1996 |
| A smart field-mounted control unit, for controlling a process, receives signals and sends a command output over a two-wire circuit which powers the control unit. An input section receives the signals, which can be instructions representative of commands or instruction sets, process v |
| 5483834 |
Suspended diaphragm pressure sensor |
January 16, 1996 |
| A pressure sensor includes a diaphragm assembly with a pair of diaphragms joined together along a rim and having spaced apart centers to form a cavity between them. A pressure input applies a pressurized fluid to external surfaces of the diaphragms. The diaphragm assembly is connected |
| 5482678 |
Organic chemical sensor |
January 9, 1996 |
| In this invention, a first sensor senses an organic gas, liquid or vapor and includes a first support having a first support surface with a layer of material fastened to it. In the presence of liquid, gas or vapor, the material swells and expands so as to vary at least one of its dimensi |
| 5436824 |
Inrush current limiter in a magnetic flowmeter |
July 25, 1995 |
| An AC powered field mounted process control transmitter includes an inrush current limiter which prevents excessive current flow to other circuitry in the transmitter. The transmitter senses a physical parameter, such as flow, and comprises a source of current, a current driven sensing |
| 5431182 |
Smart valve positioner |
July 11, 1995 |
| A valve positioner controls operation of a valve in a process control system. The valve positioner is coupled to a process control loop over which it receives a signal representative of a desired valve position and operating power for the positioner. The valve positioner controls a p |
| 5429001 |
Vortex mass flowmeter |
July 4, 1995 |
| A vortex flow transmitter has a filtering circuit receiving a noise contaminated input signal representative of flow and which has a fundamental frequency varying responsively to flow. The filter filters the input signal using one of a family of HP and LP filter characteristics to pr |
| 5426984 |
Magnetic flowmeter with empty pipe detector |
June 27, 1995 |
| An electromagnetic fluid flowmeter includes empty pipe detection circuitry. The empty pipe detection circuitry applies a common mode asynchronous signal into a pair of electrodes in the flowmeter. Impedance of fluid is determined by measuring the magnitude of the asynchronous signal betw |
| 5410730 |
Interface controller for matching a process address field from a plurality of fields and generat |
April 25, 1995 |
| An apparatus receives a query from a process controller containing a process variable address representing a storage location for a process variable in a network of field devices. A communication standard type and an unique field device address is associated with each field device. An |
| 5396810 |
Vortex flowmeter |
March 14, 1995 |
| A vortex flowmeter for measuring fluid flow includes a conduit having a wall surrounding a bore for carrying the fluid along a bore axis. A pivoting member moves in response to vortices in the fluid and extends from a hole in the wall into the bore, and sensing means is provided for |
| 5372046 |
Vortex flowmeter electronics |
December 13, 1994 |
| A vortex flow transmitter has a filtering circuit receiving a noise contaminated input signal representative of the flow and which has a fundamental frequency varying responsively to flow. The filter filters the input signal using one of a family of HP filter characteristics to produce |
| 5372045 |
Bridge pulse controlled constant current driver for magnetic flowmeter |
December 13, 1994 |
| A magnetic flowmeter system provides a volumetric flow rate output and has a coil receiving a magnetic field producing coil current from the current supply circuitry. The current supply circuitry includes an H-bridge transistor circuit having first and second switches which couple one of |
| 5355423 |
Optical temperature probe assembly |
October 11, 1994 |
| A temperature probe includes a sensor material optically communicating with a waveguide, and a sheath having a sheath coefficient of thermal expansion substantially matched to a thermal expansion coefficient of the waveguide. The waveguide has first and second ends secured proximate corr |
| 5353200 |
Process transmitter with inner conductive cover for EMI shielding |
October 4, 1994 |
| A transmitter comprises a housing, an electronics assembly, an inner cover, and an outer cover. The electronics assembly includes an actuatable switch and fits within an open-ended cavity in the housing. The inner cover is positionable over the open end to cover the electronics assembly |
| 5343762 |
Vortex flowmeter |
September 6, 1994 |
| A vortex flowmeter for measuring fluid flow includes a conduit having a wall surrounding a bore for carrying the fluid along a bore axis. A pivoting member moves in response to vortices in the fluid and extends from a hole in the wall into the bore, and sensing means is provided for |
| 5343755 |
Strain gage sensor with integral temperature signal |
September 6, 1994 |
| A strain gage pressure sensor having a resistive bridge circuit from which is measured both the applied pressure and the temperature of the pressure sensor. A constant voltage is provided across the bridge circuit such that any temperature caused changes in the resistance of the bridge c |
| 5333637 |
Pneumatic instrument particle trap |
August 2, 1994 |
| A transducer which provides a regulated pneumatic output as a function of an electric control input includes a housing, a gas regulator, and a particle trap. The housing has a passage therein, the passage including an inlet for receiving a pressurized gas supply and an outlet. The partic |
| 5333504 |
High overpressure low range pressure sensor |
August 2, 1994 |
| A low range pressure sensor includes a base plate of brittle material, and a diaphragm plate mounted on the base plate and sealed around a periphery to the base plate. Pressures are introduced to cause the diaphragm to deflect toward the base plate, and the deflection of the diaphragm is |
| 5333114 |
Field mounted control unit |
July 26, 1994 |
| A smart field-mounted control unit, for controlling a process, receives signals and sends a command output over a two-wire circuit which powers the control unit. An input section receives the signal, which can be instructions representative of commands or instructions sets, process v |
| 5331849 |
Aerodynamically shaped probe |
July 26, 1994 |
| The present invention relates to a air data sensing probe that has a cylindrical barrel joined to a contoured strut section. The strut has leading and trailing edges formed along curved paths, and supports the cylindrical barrel at a position spaced from a mounting surface and facing |
| 5329818 |
Correction of a pressure indication in a pressure transducer due to variations of an environment |
July 19, 1994 |
| A two-wire transmitter includes a pressure sensor comprising first and second sensing means each having an impedance value which varies with pressure being measured and with a predetermined environmental condition, such as line pressure or temperature. A fixed impedance has an impedance |
| 5327789 |
Electromagnetic detection system for variable area flowmeter |
July 12, 1994 |
| A variable area flowmeter employing a vertical tube containing a displaceable magnet and a closed-loop magnetic detection circuit. The closed-loop magnetic detection circuit includes first and second magnetic cores each having a sense coil and a compensation coil. The sense coil prov |
| 5323289 |
Lightning protection for field mounted instruments |
June 21, 1994 |
| A protection circuit is provided for protecting sensitive electrical field instruments from a transient voltage strike and for ensuring that the instruments will meet safety approval during high potential voltage testing. The first and second wires of a two-wire circuit are connected to |
