In-service calibration of temperature measurement devices using plant monitoring system data
AssigneeAnalysis and Measurement Services Corporation
InventorsBrent D. Shumaker, Gregory W. Morton, Hashem M. Hashemian
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Abstract
System for automating the determination of cross calibration coefficients based on data stored by a plant computer and data storage unit or a plant monitoring system. The automated system includes a processor executing software for retrieving data, determining average temperatures, determining deviations, and determining new calibration curve coefficients for deviating instruments. In another embodiment, the processor executes software for loading the historical data, selecting data points, removing deviate data, analyzing the data, reporting the data, and for recalibrating instruments that were determined to be deviating.
Claims44
An apparatus for automating cross calibrations of plant instruments, said apparatus comprising:
- a processor in communication with a data storage system, said data storage system being a part of a plant monitoring system, said processor programmed to execute a process including
- loading a data set from said data storage system, said data set including a plurality of measured process values from a plurality of instruments, said plurality of instruments including at least one redundant instrument, said plurality of measured process values including a plurality of temperature measurements obtained during isothermal conditions,
- selecting for analysis a set of data from said data set,
- removing a set of deviating data from said set of data,
- analyzing a set of remaining data for cross-calibration, and
- recalibrating any one of said plurality of instruments that produce at least one data point in said set of deviating data.
An apparatus for automating cross calibrations of plant instruments, said apparatus comprising:
- a processor in communication with a data storage system, said data storage system being a part of a plant computer system, said processor programmed to execute a process including:
- loading a data set from said data storage system, said data set including a plurality of measured process values from a plurality of instruments,
- selecting for analysis a set of data from said data set,
- removing a set of deviating data from said set of data,
- analyzing a set of remaining data for cross-calibration of said plurality of instruments, and
- recalibrating any one of said plurality of instruments that produce at least one data point in said set of deviating data, said process step of recalibrating including calculating new coefficients for said deviating instrument and calculating a recalibration uncertainty value for said deviating instrument.
An apparatus for automating cross calibrations of plant instruments, said apparatus comprising:
- a processor in communication with a data storage system, said data storage system being a part of a plant computer system, said processor programmed to execute a process including:
- loading a data set from said data storage system, said data set including a plurality of measured process values from a plurality of instruments,
- selecting for analysis a set of data from said data set, said set of data including a set of resistance temperature device (RTD) data and a set of thermocouple data,
- removing a set of deviating data from said set of data, and
- analyzing a set of remaining data for cross-calibration of said plurality of instruments, said process step of analyzing further including calculating a set of RTD deviations from said set of RTD data, calculating an average value and a standard deviation value from said set of RTD deviations, calculating a set of thermocouple deviations from said set of thermocouple data, and calculating an average of said set of thermocouple deviations.
An apparatus for automating cross calibrations of plant instruments, said apparatus comprising:
- a processor in communication with a data storage system, said data storage system being a part of a plant computer system, said processor programmed to execute a process including:
- loading a data set from said data storage system, said data set including a plurality of measured process values from a plurality of instruments,
- selecting for analysis a set of data from said data set,
- removing a set of deviating data from said set of data, and
- analyzing a set of remaining data for cross-calibration of said plurality of instruments.
An apparatus for automating cross calibrations of plant instruments, said apparatus comprising:
- a processor in communication with a data storage system, said data storage system being a part of a plant computer system, said processor programmed to execute a process including:
- retrieving a data set from said data storage system, said data set including a plurality of measured process values from a plurality of instruments,
- determining at least one average value from said data set,
- determining a set of deviating data from said data set, and
- determining new coefficients for any one of said plurality of instruments that produce at least one data point in said set of deviating data.
A computer system for automating cross calibrations of plant instruments, comprising:
- a memory medium for storing program code and a set of computer data;
- an input/output unit for communicating with a plant monitoring system, said plant monitoring system acquiring a plurality of measured process values from a plurality of instruments;
- and
- a processing unit programmed to execute a process including:
- loading a data set from said plant monitoring system, said data set including said plurality of measured process values from said plurality of instruments,
- selecting for analysis a set of data from said data set, and
- analyzing a set of remaining data for cross-calibration of said plurality of instruments.
Dependencies are inferred from the claim text.