Laser welding device, a method of checking welding condition and a method of making a center electrode for a spark plug

摘要

In a laser welding member, a photographing device is provided to photograph plasma caused by exposing laser beams to an object. An image processing member is provided to measure at least one of an area and height of a plasma image photographed by the photographing member. A distinction member is provided to compare a value measured by the image processing member with an allowable value so as to asses the laser welding condition.