Patent ID: 8428909
Filing Date: 2013-04-23
Classification: G01D,G01F

Abstract:
1. A method of using statistics to determine calibration of instruments, comprising: (a) sensing at least one critical value in a process flow by a first sensing instrument; (b) sensing the at least one critical value in the process flow by a second sensing instrument, wherein the first sensing instrument is a different type of sensing instrument than the second sensing instrument; (c) tracking relative consistency of a first set of data obtained from said first sensing instrument and a second set of data obtained from said second sensing instrument to detect a drift representing changes in mean differences between the first set of data and the second set of data occurring over a period of time; and (d) in response to detecting the drift, determining which instrument of the first sensing instrument and the second sensing instrument is a cause of the drift by identifying a change in a standard deviation in at least one of the first set of data and the second set of data.