PNNL

Abstract

Remote visual testing is typically employed to ascertain the condition of materials in componentsthat are inaccessible for direct examination. In the power and petrochemical industries, remotevisual testing is used to assess whether service-related degradation is being manifested that, if leftunchecked, may eventually impair the structural reliability of a component. Several codes andstandards require that visual examinations be periodically conducted. Many of these inspectionsmust be performed remotely due to harsh environments or design geometries of the subjectcomponents. This paper describes the attributes and limitations of remote visual testing,performance demonstration standards for camera systems, typical dimensions for service-induced cracking phenomena, and an assessment of the reliability of remote video camerasystems at finding cracks. Because many forms of service-induced cracks have very small crackopening dimensions, the reliability of remote visual testing may not be adequate to ensurecomponent integrity, given the capabilities of current camera systems and application practices.