Bikini type 6003 temperature level control instrument by Fielden Electronics Ltd, Manchester, c.1967.

The Bikini was developed in the early 1960s, initially to control temperature but later to control other factors such as rate of flow and level. The Bikini was so called because it consisted of two main parts, mechanical and electrical, both of which had been made as small as possible. This instrument could be used at a distance and allowed central control of many different points in a process.