Online monitoring technology to extend calibration intervals of nuclear plant pressure transmitters
Online monitoring (OLM) technology can be used in nuclear power plants as an analytical tool to measure sensor drift during plant operation and thereby identify the sensors whose calibration must be checked physically during an outage. The technology involves a procedure to (1) retrieve redundant sensor measurements from the process computer or through a separate data acquisition system, (2) calculate the average of these measurements and the deviation of each sensor from the average, and (3) identify any sensor that has deviated beyond its predetermined monitoring limit.