Fiber optical measuring device with a frequency sensitive transducer

摘要

The invention relates to a fiber optical measuring device for measuring physical quantities such as temperature and pressure, comprising a measuring transducer comprising a sensor material, an electronic unit comprising an evaluating electronic system, light sources and photo-detectors, and one or more optical fibers which connect said transducer to said electronic unit. The invention is characterised in that the sensor material has optical properties dependent on the modulating frequency of the light, such as absorption, reflection or luminescence; that the light from the electronic unit is arranged to be modulated by one or more frequencies; that at least one of these frequencies lies within the frequency range where the optical properties of the sensor material are influenced by at least one of said physical quantities; and that the modulating amplitude and/or the modulating phase position of the light emanating from the sensor material is/are arranged to be detected in the electronic unit at at least one of said modulating frequencies.