The use of robotic welding in industry is well documented. Further automation will involve the use of sensors with feedback to carry out such tasks as seam tracking or weld penetration monitors. The paper describes a seam tracker for TIG welding. It uses a standard black and white television camera to view the light reflected from the components being welded. The light source is a halogen tungsten lamp. High-speed digitisation using a microcomputer enables rapid correction for any misalignment. All the components used are standard, so that a low-cost system may be produced.