Novel thin wire paint and sealant degradation sensor

Very thin corrosion sensors have been developed to detect the degradation of paints and sealants and for application in bolts and joints to detect the ingress of the environment due to failure of corrosion protection coatings. The sensors are based on thin insulated wires that have had the insulation removed over small regions by laser micro-machining. The sensors can be interrogated with very simple instrumentation, such as an Ohm meter, however, in this paper we have used a low power, networked sensor interface developed at the Defence Science and Technology Organisation. This paper presents the fabrication of the sensors, theoretical sensor responses and experimental results from sensors deployed on bare metal and under paint, and then exposed to salt water.