A digital signal processing scheme for measurement of exponentially decaying signals, such as those found in fluorescence lifetime-based fiber-optic sensors, is discussed. To measure the time constants of the exponential decay, the system uses modified digital phase-sensitive-detection with the phase locked to a fixed value and the modulation period tracking the measured lifetime. A key feature of this system is its ability to compensate for correlated and uncorrelated offsets of the decay signal and to work with very low signal-to-noise ratio (SNR=3). The test results give a typical resolution of 0.05% for slow decay (λ>500 μs) and of 0.1% for fast decay. The system nonlinearity, after the correction for the electronic time constant, is 0.1%. Such a system has been applied to measuring the fluorescence decay time of a chromium-doped YAG crystal used as a sensing element of a fiber-optic thermometer. The calibration of the thermometer has shown a temperature resolution of 0.1°C from -25°C to 500°C

Digital signal processing for fiber-optic thermometers / Fernicola, Vito; Crovini, L.. - In: IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT. - ISSN 0018-9456. - 44:2(1995), pp. 447-450.

Digital signal processing for fiber-optic thermometers

FERNICOLA, VITO;
1995

Abstract

A digital signal processing scheme for measurement of exponentially decaying signals, such as those found in fluorescence lifetime-based fiber-optic sensors, is discussed. To measure the time constants of the exponential decay, the system uses modified digital phase-sensitive-detection with the phase locked to a fixed value and the modulation period tracking the measured lifetime. A key feature of this system is its ability to compensate for correlated and uncorrelated offsets of the decay signal and to work with very low signal-to-noise ratio (SNR=3). The test results give a typical resolution of 0.05% for slow decay (λ>500 μs) and of 0.1% for fast decay. The system nonlinearity, after the correction for the electronic time constant, is 0.1%. Such a system has been applied to measuring the fluorescence decay time of a chromium-doped YAG crystal used as a sensing element of a fiber-optic thermometer. The calibration of the thermometer has shown a temperature resolution of 0.1°C from -25°C to 500°C
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11696/34520
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 9
  • ???jsp.display-item.citation.isi??? ND
social impact