SIMULTANEOUS, PHASE-SENSITIVE DIGITAL DETECTION PROCESS FOR TIME-RESOLVED, QUASI-SIMULTANEOUSLY CAPTURED DATA ARRAYS OF A PERIODICALLY STIMULATED SYSTEM

摘要

A process for measurement and analysis technology supplies by phase-sensitive detection the response of a system that may be periodically stimulated. For that purpose, an external thermodynamic parameter is periodically modified. Data arrays are used instead of the scalar measurement values normally used in the state of the art both for capturing and for processing data. During data processing, the period is subdivided into a determined number of supporting points that represent each a data vector at the corresponding moment in time within the period. The supporting points of at least one period are digitally stored after simultaneous phase-sensitive detection is carried out. By simultaneously processing the measurement data, the number of components of the data array is reduced in time while maintaining the signal/noise ratio at the same level. The phase angle array, which represents for each component the delay of the system response in relation to the stimulation, is an essential element to characterise the kinetics of the stimulated process. Devices for Fourier transformation infrared and X-ray diffraction modulation are disclosed. The process has application in optical spectroscopy, in diffraction methods, in image processing, and in general in measurement techniques which use unidimensional or bidimensional array detectors, or fast (almost simultaneous) serial data capture.