Process temperature transmitter with improved temperature calculation
A technology of temperature transmitter and analog-to-digital converter, applied in the direction of thermometer, thermometer test/calibration, thermometer with electric/magnetic components directly sensitive to heat, etc. Measurement accuracy, etc.
Active Publication Date: 2013-07-17
ROSEMOUNT INC
View PDF5 Cites 0 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
In some environments, this update rate may be too slow for users to accept
While the update rate can be greatly increased if the reference scan is omitted, the accuracy of the temperature measurement may be unduly degraded
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
Embodiment Construction
[0008] figure 1 is a diagrammatic view of a process temperature transmitter for which embodiments of the present invention are particularly useful. The process temperature transmitter 12 includes a loop communicator 20 , a plurality of sensor terminals 22 , a current source 24 , a voltage measurement device 26 , a controller 28 and a switch / multiplexer 30 .
[0009] Loop communicator 20 is coupled to process control loop 16 (shown in phantom) and is adapted to communicate over process control loop 16 . Process control loop 16 is any physical configuration capable of communicating signals related to process information. For example, process communication loop 16 may be a two-wire 4-20mA process communication loop. A process variable transmitter coupled to such a process communication loop controls the amount of current flowing through the loop such that the current corresponds to the process variable. In some process communication loop embodiments, the energization level is ...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More PUM
Login to View More Abstract
In a process temperature transmitter, a method for providing a process temperature output is described. The method includes providing a measurement current through a circuit including a reference resistor and a resistance temperature device (RTD). A first voltage across the reference resistor is measured while the measurement current flows through it. A first voltage across the RTD is also measured while the measurement current flows through it. A first resistance of the RTD is calculated based on the measured voltage across the reference resistor and the measured first voltage. A first process temperature output is provided based on the first resistance of the RTD. A second voltage is subsequently measured across the RTD while a measurement current flows through it. A second voltage across the reference resistor is then estimated based on the measured second voltage across the RTD and the measured first voltage across the reference resistor. A second resistance across the RTD is calculated based on the measured second voltage and the estimated second voltage. A second process temperature output is provided based on the second resistance.
Description
Background technique [0001] The process industry uses process variable transmitters to monitor process variables related to substances such as solids, slurries, liquids, vapors and gases in chemical plants, pulp mills, petroleum plants, pharmaceutical plants, food plants and other fluid handling plants . Process variables include: pressure, temperature, flow, level, turbidity, density, concentration, chemical composition, and other properties. Process temperature transmitters provide an output related to the sensed process temperature. The temperature transmitter output is typically communicated over a process communication loop to a control room or other process equipment so that the process can be monitored and / or controlled. To monitor process temperature, temperature transmitters typically include or are coupled to a temperature sensor, such as a resistive temperature device (RTD). [0002] RTDs change resistance in response to changes in temperature. By measuring the ...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More Application Information
Patent Timeline
Login to View More Patent Type & Authority Patents(China)
IPC IPC(8): G01K7/20G01K15/00
CPCG01K15/00G01K7/20G01K15/007
Inventor 詹森·H·鲁德劳伦·M·安格斯塔德
Owner ROSEMOUNT INC