초록 ▼

A photoluminescent indicator apparatus having automatic feedback means to maintain the sensitivity of the indicator apparatus with respect to variations in environmental conditions. The apparatus includes a sample of photoluminescent material having a photoluminescent decay rate which varies as a fu

A photoluminescent indicator apparatus having automatic feedback means to maintain the sensitivity of the indicator apparatus with respect to variations in environmental conditions. The apparatus includes a sample of photoluminescent material having a photoluminescent decay rate which varies as a function of environmental conditions. The sample is positioned in a remote location having some unknown aspect of the environment desired to be measured. The sample is optically excited with a modulating signal to generate an excitation output signal functionally dependent on the modulating signal and indicative of the unknown environmental condition. A phase detection means is provided for comparing difference in phase between a phase reference signal and the excitation output signal to generate a phase differential signal functionally related to the photoluminescent decay rate of the sample. The indicator apparatus includes an automatic feedback means for adjusting the phase reference signal in accordance with the phase differential signal.

대표청구항 ▼

A photoluminescent indicator apparatus comprising: a. a photoluminescent material having a photoluminescent decay rate which varies as a function of environmental conditions; b. a signal generating means having a phase reference signal means for generating a reference signal, and a signal source mea

A photoluminescent indicator apparatus comprising: a. a photoluminescent material having a photoluminescent decay rate which varies as a function of environmental conditions; b. a signal generating means having a phase reference signal means for generating a reference signal, and a signal source means for generating a modulating signal; c. means for optically exciting a first sample of said photoluminescent material in accordance with a first modulated signal from said modulating signal source to generate an excitation output signal functionally dependent on said first modulating signal and indicative of said environmental conditions; d. phase-detection means for comparing the difference in phase of said reference signal and said excitation output and for generating a phase differential signal functionally related to the photoluminescent decay rate of said first sample; and e. feedback means for adjusting said reference signal in accordance with said phase differential signal.