Patent ID: 7038209
Filing Date: 2006-05-02
Classification: G01N

Abstract:
1. Device for detecting thermal conductivity of a sample by application of optical pulse techniques, comprising a furnace for heating the sample to a predetermined temperature, a source of radiation for emitting high-energy radiation in the form of pulses onto said sample for heating the sample, an infrared sensor for detecting time history of infrared radiation emitted by said sample, a decoupler element for decoupling a reference radiation from a beam emitted by said source of radiation, a second sensor for measuring said reference radiation, as well as an analyzer unit for detecting the thermal conductivity of the sample by analyzing signals of said infrared sensor, said second sensor for measuring said reference radiation having a bandwidth that is substantially wider than a reciprocal value of pulse length of said source of radiation, said analyzer unit being so designed that it detects the thermal conductivity by deriving it from the signals of said infrared sensor, which are corrected by performing a convolution with the measuring signals of said second sensor by approximating a laser pulse by sections in at least two sections by means of exponential functions, and said analyzer unit being designed for detecting a time difference between a rated zero point in time and a starting point of the approximated laser pulse.