Quite used in refrigeration, this type of manometer works based on the following principle: a copper pipe, with elastic property and in circular form, also denominated tube of Bourdon, is connected to a rod, forming this a connection.
Cooling fluid entering the Bourdon tube through a hole in the connecting rod with raising the pressure causes the tube to change its shape and expand by dragging with it a spring a rotating gear whose movement Is transferred to a pointer.
The applied pressure can be read on a suitably graduated scale. The pressure recorded by the Bourdon gauge is known as gauge pressure.
