A type K thermocouple surface probe, with a low mass fast response sprung tip. The tip comprises a thin metallic disc approximately 4mm diameter, which has attached to it the thermocouple junction. This makes the probe ideal for use on low thermal mass devices, where minimum heat sink effect is required, The thermocouple is protected by a 5 mm diameter stainless steel sheath with a splayed tripod end and is supplied with a miniature thermocouple plug fitted.