Several associated techniques and fiber optic constructions are disclosed to protect a diaphragm type fiber optic cylinder pressure sensor from the effects of maximum under hood temperatures and to minimize errors associated with rapidly changing under hood and engine temperatures. This enclosure prevents the active metal from deleterious reaction with the environment external to the anode compartment, which may include aqueous, ambient moisture, andor other materials corrosive to the active metal. The connecting element further comprises at least one latching means for fixing the slide in the second position and at least one releasing means for manually acting onto the at least one latching means in order to release the slide from the second position for the unlatching of the releasable connection between the engaging element and the receiving element. The sensor body has an opening that receives a portion of the float. However, as the inflatable cell is formed in a convex shape that projects downwardly, the inflatable cell resists being pulled up and is, therefore, prevented from being bent.