Process and device for the optical measurement of temperature and process for the production of a suitable probe
OwnerJean D. Tschirren, Gilbert C. Widmer +3inventors
InventorsJean D. Tschirren, Gilbert C. Widmer, Jean-Paul Pellaux, Andre Coche, Marcel R. Samsel
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Abstract
The disclosed invention concerns a process for the optical measurement of temperature, a probe device for the carrying out of the process, and a process for producing probe. The probe device contains a pellet of liquid crystals which is contained within an envelope and arranged at the end of an optical fiber. The optical fiber receives light, which is continuously swept by different wavelengths and the light reflected by the liquid crystal is analyzed to detect the reflection peaks and deduce the probe temperature.
Claims14
A process for the optical measurement of temperature employing a source for emitting light in a given range of wavelengths, a light-conductive device for transmitting light within at least a part of the wavelength range, a cholesterol-crystal probe and a detector device, characterized by filtering the light emitted by the source so as to produce a light which sweeps continuously and uniformly said range of wavelengths, transmitting the light thus produced through said light conductive device to the said cholesterol-crystal probe, detecting at least a part of the light reflected by the said crystals by said detection device, and measuring the temperature in the vicinity of the probe by measuring the sift between a reference signal produced at the start of each sweep cycle and a peak signal corresponding to the maximum reflection of the light on the crystals for a given wavelength of the said wavelength range.
A device for the optical measurement of temperature comprising source means for emitting light in a given wavelength range;
- a light-conducting means for transmitting light in a least a part of the said wavelength ranges;
- a cholesterol-crystal probe;
- detection means;
- filtering means for the light emitted by the source so as to produce a light which sweeps continuously and uniformly the wavelengths of said wavelength range;
- means for producing a reference signal at the start of each sweep cycle;
- means connected to the detection means to produce a peak signal corresponding to each peak value of the amount of light reflected by the said crystals and detected by said detection means;
- means for measuring the shift between the reference signal and the peak signal and for displaying the temperature in the vicinity of the probe as a function of the shift measured;
- said light-conducting device formed of a single optical fiber in order to transmit the light incident on the crystals and the light relfected by the crystals.
A process for producing a probe for optical measurement of temperature employing a source for emitting light within a given wavelength range, a single optical fiber for transmitting light emitted by said source and swept continuously and uniformly in wavelength within the said wavelength range, and a means for detecting a part of said light of continuously varying wavelength after reflection on cholesterol crystals, characterized by selectivity chemically attacking the end section of the optical fiber in such a manner as to form a substantially parabolic cavity within the fiber in the central zone corresponding to the core, stretching the protective envelope of synthetic material so that it extends beyond the transverse fracture surface of said fiber, depositing a pellet of cholesterol crystals in said cavity on the fracture surface, and welding the end of the stretched protection envelope to enclose the crystals within the closed pocket.
Dependencies are inferred from the claim text.