Abstract:
A sensor system comprises a process transducer, a unpowered vibration sensor, and a process transmitter. The process transducer is disposed within a thermowell and configured to produce a first sensor signal. The unpowered vibration sensor is configured to produce a second sensor signal reflecting vibration of the thermowell. The process transmitter is configured to receive, process, and transmit the first and second sensor signals.
Abstract:
A multiplexed input/output (I/O) system detects leakage currents on a selected input channel. The system includes a leakage detection multiplexer connected to provide an output selected from one of a plurality of input channels. In addition, the leakage detection multiplexer provides as part of the output measured leakage currents associated with the selected input channel. Based on the detected leakage currents, a determination can made regarding whether the detected leakage currents have compromised the integrity of the multiplexer output. In addition, the detected leakage current can be used to compensate the output provided by the multiplexer to account for the presence of leakage currents on the selected channel.
Abstract:
A system for measuring temperature includes a thermowell, a primary temperature sensor, a reference sensor, and a transmitter. The thermowell has a measurement instrument connection and a side port. The primary temperature sensor extends into the thermowell through the measurement instrument connection, and the reference sensor extends into the thermowell through the side port. The transmitter is connected to each of the primary temperature sensor and the reference sensor. The transmitter has circuitry for measuring temperature based upon signals received from the primary temperature sensor and for concurrently calibrating based upon signals received from the reference sensor.
Abstract:
A method includes sensing a process parameter to generate a sensor signal that includes a process signal and line noise components (102), digitizing the sensor signal at a sample rate (102), detecting line noise zero crossings in the sensor signal (104), determining a line noise frequency as a function of the detected line noise zero crossings (106), and adjusting the sample rate as a function of the line noise frequency to reduce an impact of line noise on the digitized sensor signal (110).
Abstract:
An industrial process temperature transmitter (100) for measuring a temperature of a process medium (102) includes a temperature sensing unit (104), a compensation circuit (120), and an output circuit (126). The temperature sensing unit includes a process temperature sensor (105A) that is separated from the process medium by an isolation wall (108). The temperature sensing unit (104) is configured to produce a temperature signal (122) that is indicative of the temperature of the process medium (108) based on a process temperature signal output (106A) from the process temperature sensor (105 A) during a temperature measurement. The compensation circuit (120) is configured to compensate the temperature signal (106A) for a response time of the temperature measurement to a change in the temperature of the process medium (102), and output a compensated temperature signal (122). The output circuit (126) is configured to produce a temperature output (128) as a function of the compensated temperature signal (122) corresponding to the temperature of the process medium (108).
Abstract:
A sensor system comprises a process transducer, a unpowered vibration sensor, and a process transmitter. The process transducer is disposed within a thermowell and configured to produce a first sensor signal. The unpowered vibration sensor is configured to produce a second sensor signal reflecting vibration of the thermowell. The process transmitter is configured to receive, process, and transmit the first and second sensor signals.
Abstract:
A field device (108) for use in an industrial process (100) includes a housing (110) having a cavity (112) formed therein. A humidity-sealed electronics module (126) has a first compartment (146) formed therein and is positioned in the cavity (112). The humidity-sealed electronics module (126) includes a seal board. The seal board separates the first compartment (146) of the humidity sealed electronics module (126) from a second compartment (130) in the housing (110). A first electrical component (124) in the first compartment (146) is mounted to the seal board and a second electrical component (122) in the second compartment (130) is electrically connected to the first electrical component (124).
Abstract:
An infrared sensor (10) includes a thermopile (16) connected in series with an ambient temperature compensation resistance temperature detector (RTD) (18) and four electrical leads (20, 22, 24, 26). The thermopile (16) produces a voltage as a function of temperature of a point of interest, while the RTD (18) varies in resistance as a function of ambient temperature. Two of the leads (22, 24) deliver current to energize the RTD (18). The other two leads (20, 24) of (26) are used for sensing voltages produced by the thermopile (16) and the RTD (18).