Automatic linearity calibration in a resistance thermometry bridge

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Automatic linearity calibration in a resistance thermometry bridge (241.87 KB)

The paper describes a new system that automatically calibrates the linearity of a resistance thermometry bridge or readout. A thermometry bridge, like all measuring and test equipment, must be regularly tested to ensure it is operating properly and accurately. Previously, this could only be done using special equipment and time-consuming procedures. The new technique described in the paper facilitates more frequent calibration of a resistance thermometry bridge. The system is incorporated into the design of the bridge and thus requires no extra equipment. Calibration, once initiated, is performed automatically by the bridge and is relatively fast.
Tests were performed to evaluate the effectiveness of the automatic linearity calibration method. The uncertainty analysis and test results presented in the paper indicate that the technique is capable of quantifying resistance ratio measurement error as small as 2 × 10-8 and is effective at identifying a wide variety of failures when they occur.

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