Fouling detection and compensation in Clark-type DOx sensors

Author

Fraher, Patrick M A ; Clarke, David W.

Author_Institution

Dept. of Eng. Sci., Oxford Univ., UK

Volume

47

Issue

3

fYear

1998

fDate

6/1/1998 12:00:00 AM

Firstpage

686

Lastpage

691

Abstract

Clark-type dissolved oxygen (DO) sensors are used in process control and environmental monitoring applications. A common fault affecting the accuracy of DO sensor measurements is fouling: the build-up of surface agents on the membrane of the sensor. This paper outlines a technique to detect and compensate for DO sensor fouling, and hence make these instruments more robust and reliable. The technique uses an accurate model of the sensor´s transient response to provide a value of the oxygen transfer time τ in the membrane. This new value of transfer time is compared with the initial unfouled value and the measurement is compensated by a factor related to the fouling-induced changes in τ. The measurement uncertainty associated with both normal and corrected measurements is examined

Keywords

electrochemical sensors; error compensation; fault diagnosis; intelligent sensors; measurement uncertainty; oxygen; process control; transient response; water pollution measurement; Clark-type dissolved oxygen sensors; O; SEVA model; build-up of surface agents; compensation; electrochemical electrodes; environmental monitoring; fault diagnosis; fouling detection; intelligent sensors; measurement uncertainty; oxygen transfer time; process control; self-testing; sensor membrane; transient response; Biomembranes; Electrodes; Fault detection; Intelligent sensors; Measurement uncertainty; Monitoring; Pollution measurement; Robustness; Water pollution; Water resources;

fLanguage

English

Journal_Title

Instrumentation and Measurement, IEEE Transactions on

Publisher

ieee

ISSN

0018-9456

Type

jour

DOI

10.1109/19.744325

Filename

744325