Principle of the PortaSCAN XBS: a non-destructive gamma ray-based instrument for the assessment of timber structures

The PortaSCAN XBS is an inspection device that is used to assist an operator to assess the integrity of a wooden structure. The wood is expected to be seasoned, dry timber, as gamma rays cannot distinguish between water and wood. It compares the response of a suspect surface to a sound surface and a loss of response is interpreted as a loss of depth in the surface, with sensitivity to around 100mm for hardwood timbers. The response loss could equally be a loss in density through the bulk of the object. An operator can then use this information as an aid for assessing the overall integrity of the wooden structure. In the case of structures such as piles or power poles where the timber is vertical, the PortaSCAN XBS goes further and can also provide an estimate of the available bending moment of the pole. In summary, the PortaSCAN XBS is a portable density gauge that uses gamma rays to identify variations in timber density. The concept is for a portable, safe, quick and simple tool to assist inspectors in understanding what lies beneath the surface of the timber they are examining. Through robustness in design and with a number of safety features, the user and the public is protected from any risk associated with its use.