Methods for fabricating an apparatus having a hermetic seal

A method of sealing a sensor to a housing comprising:

• providing a housing with a top and a bottom and a hole that passes through the housing from the top to the bottom wherein the housing further comprises a first cavity with a first inner wall, a first outer wall and a first cavity bottom and wherein the housing further comprises a second cavity with a second inner wall, a second outer wall and a second cavity bottom and both the first cavity and the second cavity extend down into the housing from the top and surround the hole wherein the first outer wall of the first cavity is the second inner wall of the second cavity;
• providing a seal with a toroidal shape with an open seal top;
• pressing the seal inside the first cavity such that a seal bottom is pressed against the first cavity bottom;
• providing an isolation member coupled to the sensor;
• placing the isolation member down into the first cavity such that the isolation member extends down into the open top of the seal;
• placing a collar down into the second cavity;
• and
• pressing the collar down such that the collar deforms the second inner wall of the second cavity and seals the housing to the isolation member.