A DSP-based measuring system for temperature compensated fiberoptical oxygen sensors

A new signal processing approach for fiberoptical sensors, microoptodes, is presented. All signal generation and processing is completely based on a fast, low-cost DSP (Digital Signal Processor). This enables the implementation of new features such as a simultaneous multi-frequency measurement to resolve different analytical parameters in the luminescence signal. For instance, a hybrid sensor was applied to simultaneously sense the temperature and oxygen concentration, and the temperature information was used to compensate for the temperature effect on the oxygen measurement. As a further benefit, recent improvements in indicator chemistry and fiber tip preparation also yield a luminescence signal level high enough to be detected with a common photodiode instead of a photomultiplier tube. Consequently, the combination of small detectors and highly integrated DSPs enable portable, handheld measurement devices with very little calibration requirements.