This International Standard specifies general requirements and test methods for sheath-type glow-plugs. Detailed test condition(s) and/or requirement(s) are agreed between the glow-plug manufacturers and the engine manufacturer. It is applicable to those sheath-type glow-plugs conforming to ISO 6550-1, ISO 6550-2, ISO 6550-3 and ISO 6550-4, used in compression ignition (diesel) engines.