Bimetallic thermometers can be classified into four types based on the connection direction between the pointer dial and the protective tube: axial type, radial type, 135° type, and universal type.
① Axial type bimetallic thermometer: The pointer dial is connected perpendicularly to the protective tube.
② Radial type bimetallic thermometer: The pointer dial is connected parallel to the protective tube.
③ 135° type bimetallic thermometer: The pointer dial is connected at a 135° angle to the protective tube.
④ Universal type bimetallic thermometer: The connection angle between the pointer dial and the protective tube can be adjusted arbitrarily.
