Although their image quality may not equal that of rigid borescopes, video endoscopes are powerful tools for a variety of inspection jobs where the working area is inaccessible or hidden. These devices have a thin tube, rigid or flexible, that can fit into a small gap or hole, and beams back images to enable detailed remote visual inspections of for example weld quality in new-build, or corrosion in reactor system pipework. The key technical difference between the two is the way the image is transmitted. A borescope is essentially a rigid hollow tube that carries an image focused from a lens on one end to an eyepiece on the other. As it relies on optics, its image quality is probably superior, but its shape is limited to a straight rigid tube. Videoscopes contain a camera in the tip which converts an optical image into an electrical signal, which is transmitted to a processor at the near end along a cable that runs the length of the probe, which is flexible. Borescopes tend to be the least expensive of the three devices, and videoscopes the most; a third category, flbrescopes, which are intermediate in price but not examined here, channel an optical image through flexible fibre-optic cables). Despite their cost, videoscope systems have evolved to suit many industrial needs.
展开▼
