Patent ID: 8742768
Filing Date: 2014-06-03
Classification: G01N

Abstract:
1. An interrogation measurement circuit arranged to determine at least one property of a target material, the interrogation measurement circuit comprising: a frequency control functionality; at least one signal source responsive to said frequency control functionality and arranged to output a time varying signal comprising frequency content over a range of frequencies; a transducer in communication with said at least one signal source and arranged to output a first portion of the time varying signal so as to interact with the target material; a receiver arranged to receive the first portion of the time varying signal after interaction with the target material; a receiver arranged to receive a second portion of the time varying signal that doesn't interact with the target material thereby providing an internal reference copy of the time varying signal; a propagation delay calculation functionality arranged to determine the propagation delay of said received time varying signal at each of a plurality of frequencies over the range of frequencies by comparison of said first portion of time varying signal that was perturbed by the interaction with said material to the said internal reference copy of the time varying signal; and a property determining functionality arranged to determine at least one property of the target material responsive to the determined propagation delay at each of the plurality of frequencies.