Patent ID: 9086364
Filing Date: 2015-07-21
Classification: G01N

Abstract:
1. A photoacostic detector comprising: a sensing chamber; control circuits coupled to the sensing chamber, the control circuits include a pre-stored representation of a detector transfer function indicative of detector performance wherein the detector transfer function is measured by varying a source of radiant energy injected into the sensing chamber between multiple intensity values while sensing and measuring a photoacoustic output wherein the pre-stored representation of the detector transfer function is compared to a current transfer function, and, which includes circuitry to determine at least one compensation value; circuitry to combine at least one compensation value with at least one current indicator of gas concentration; at least one acoustic transducer carried adjacent to the chamber where the control circuits are coupled to the transducer, where the control circuits receive a first electrical signal from the transducer and including processing circuits, which, over a predetermined time interval, process the first electrical signal from the transducer to increase the signal-to-noise ratio thereof; a second acoustic transducer carried adjacent to the chamber and where the processing circuits process a second electrical signal, from the second acoustic transducer and confirmation circuitry to determine that first and second ambient-noise corrected signals, obtained from the first and second electrical signals, exhibit a constant amplitude ratio and a fixed phase relationship, and which responsive thereto, generates an indicium indicative thereof.