A Bourdon tube pressure gauge has an elastic tube that's soldered or welded toward just one facet right into a socket. An adjustment of pressure brings about a deflection during the tube; this is proportional on the used pressure and is shipped to your rotary gear by using a pointer. https://auto-parts76319.blogkoo.com/the-fact-about-diaphragm-pressure-gauge-that-no-one-is-suggesting-50823134