USA Lab THERMO-5L Thermo Well, 24/40", 5L

USA Lab Glass Thermowell is a device to reduce the risk of leaks while taking temperature readings. It is basically a long glass tube which is sealed on one end and partially filled with a fluid to transfer heat such as silicone oil. A thermometer is inserted into the tube and the sealed end would typically be immersed in the contents of a boiling flask which transfer heat to the thermometer and allow temperature readings to be taken. The opposite end has a female 24/40 joint for an air tight and dependable seal.

The 24/40 joint should be greased to allow a tight and secure seal.