US Patent 10578503 System and methods for strain detection in a coupling

A fitting for a fluid conduit includes a coupling body, a coupling nut, a conduit gripping device that is axially driven by the coupling body and the coupling nut to provide grip and seal against a conduit, and a strain sensor unit disposed on a neck portion of the coupling body, the strain sensor unit including at least a first axially extending strain sensor positioned and oriented for strain sensor unit measurement of a first strain of the neck portion corresponding with a first fitting assembly condition, and a second strain of the neck portion corresponding with a second fitting assembly condition different from the first fitting assembly condition.