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Optical scattering spectra and angular distribution of scattering intensities were evaluated using concentrated orange juice. The concentrated orange juice was opaque due to the scattering particles included. In these specimens, the scattering intensities and angular distribution of the scattering intensities varies with the refractive index ratio of the scattering particles against the liquid surrounding the particles. The sugar concentrations of orange juice, which are linearly correlated with the refractive index of the specimens, can therefore be measured by the scattering intensities and their angular distributions. The scattering intensities measured using a halogen lamp, a white LED, a yellow LED, a red LED and near-infrared LEDs (λ = 850 nm and 940 nm) vary linearly with the sugar concentrations of the specimens. The gradient and correlation coefficient of the calibration lines fitted are found to vary with the scattering angles, θ. A non-destructive evaluation of the sugar concentrations of orange juice can be measured sensitively at θ = 170 or 160 °s with any incident lights which are scattered from the specimens.

Mn doped spinel (MgAl 2 O 4 ) crystals have been grown by floating zone (FZ) techniques with various conditions of O 2 concentrations in the growth atmosphere from 0 to 75 vol%, with a starting composition of molar ratio x= MgO/(MgO+Al 2 O 3 ) from 0.3 to 1.0 and/or Mn concentrations from 1.0 to 6.0 at%. Optical absorption spectra and photoluminescence spectra were evaluated using crystals grown under various growth conditions. The color of the crystals is found to vary with their composition and the O 2 concentration in the atmosphere. Crystals grown under a 100 vol% Ar atmosphere, were a pale green color and emitted a strong green luminescence at λ =520 nm. Colors of stoichiometric crystals, x =1.0, and Mg-poor crystals grown under an oxidizing atmosphere are yellow and red, respectively. Both optical absorption spectra and photoluminescence spectra of Mg-poor, x 2 –Ar) atmosphere are found to vary greatly from those of the stoichiometric crystals.

X-ray excited visible light luminescence were evaluated from Cr doped Y3Al5O12 (YAG) crystals using an X-ray powder diffractometer adapting a fiber spectrometer, a digital camera, and a LED illumination. Red colored luminescence peaking at λ = 678, 690, 708, and 726 nm were observed from Cr doped YAG under irradiation by both CuKα X-ray and a violet LED (λ = 405 nm). Peak wavelengths of X-ray excited luminescence are the same as those of photoluminescence (PL). The peak intensities of X-ray excited luminescence, which increases linearly with X-ray strength, increases up to Cr concentration at around 0.5 mol%, then decreases gradually with Cr concentration due to a concentration quenching. It was found that the concentration quenching of X-ray excited luminescence occurs at a lower concentration at around 0.5 mol% than that of PL at around 3.5 mol%.

A fluorescent temperature sensor using temperature dependence of fluorescent inorganic materials is studied for low temperature measurement. Ruby (chromium ions doped sapphire) is used as a sensor head of the fluorescence thermometer because of long photoluminescence (PL) lifetime and visible emission. In this research, ruby crystal is found to be useful as the sensor head for fluorescence thermometer. In addition, the ruby crystal is potentially useful material for the sensor head crystals to measure low temperature below 0 °C.

Concentrations of vitamin B2 in milk were evaluated based on photoluminescence (PL) peak intensities at around λ = 545 nm. PL was measured in a back-scattering configuration using a 3.2 mm diameter optical fibre bundle irradiated by ultra-violet LEDs, violet LEDs or a blue LED as the excitation light. The tip of the optical fibre bundle was dipped into commercially available whole milk, low-fat milk and non-fat milk. PL peaking at 545 nm was observed under LED irradiation. Vitamin B2 concentrations were measured using a standard addition method and a calibration curve method. Deviation between the vitamin B2 concentration measured by PL using a standard addition method and those by HPLC technique varied with wavelength of excitation light and was smallest with violet LED (405 nm) excitation. The standard deviation of results measured by PL using a calibration curve method was better than those using a standard addition method.

A novel thermoelectric type hydrogen gas sensor based on exothermic reaction of hydrogen storage alloy is proposed and fabricated. First, an exothermic reaction of a hydrogen storage alloy at room temperature has been studied for a hydrogen gas sensor application. Next, a copper (Cu) constantan thermocouple painted a palladium (Pd) past on surface was fabricated as a hydrogen gas detector. The response characteristic of the fabricated hydrogen gas detector was evaluated under hydrogen gas flow. The exothermic reaction of Pd and hydrogen gas was successfully observed using fabricated gas detector. It was clarified that the fabricated hydrogen gas detector using Cu constantan thermocouple with Pd is potentially useful for hydrogen gas sensor material.

Spinel (MgAl 2 O 4 ) crystals doped with 1.0% Mn have been grown by floating zone (FZ) technique with various Mg compositions, x = MgO/Al 2 O 3 , from 0.2 to 1.0. Compositional variations of photoluminescence are evaluated for a fluorescence thermometer application using crystals grown. Strong photoluminescence (PL) peak is observed at λ from 512 to 520 nm from the crystals grown from compositions, x , from 0.3 to 1.0. Peak wavelength of PL increases linearly from 512 to 520 nm with x . Weak PL peaking at λ = 750 nm is also observed from the specimens. Compositional variations of PL are considered to be due to the variation of crystal field surrounding the Mn 2+ ions. The variation of crystal field strength agrees with the compositional variation of lattice constant.

Eu 2 O 3 doped Y 3 Al 5 O 12 (YAG) crystals have been grown using a floating zone technique and evaluated thermal stability and annealing behavior of PL for a fluorescence thermo-sensor application. Color of the crystals grown varies from deep purple to colorless with O 2 concentration of the growth atmosphere and annealing in air. Photoluminescence (PL) peaking at λ = 590, 607, 624, 647 and 709 nm due to Eu 3+ ions are observed from the crystals under UV excitation. Anomalous temperature dependence of PL intensity, which is observed in as-grown crystals, is improved greatly by annealing through the heat cycle. From annealing behavior of optical absorption spectra, residual Eu 2+ ions are suggested to be responsible for the de-coloration and the improvement of anomalous temperature dependence of Eu doped YAG crystals.

Red colored bright visible light fracto-mechanoluminescence was observed successfully from ruby (Cr doped Al2O3) and Cr doped spinel (Cr doped MgAl2O4) crystals in mechanical processes such as cutting, grinding and polishing. Fracto-mechanoluminescence spectra from ruby (peaking at λ=696 nm) and Cr doped spinel (peaking at λ=693 nm) perfectly agree with those of photoluminescence (PL) from Cr3+ ions in ruby and spinel crystals, respectively. In the grinding and polishing processes, peak intensities and peak wavelength of fract-mechanoluminescence from ruby and Cr doped spinel crystals varies with roughness (grain size, #) of the diamond disk. Fracto-mechanoluminescence is expected to be used in the in-situ evaluation of fracture of crystals in cutting, grinding and polishing for highly precise mechanical processes.

Photoluminescence and visible light thermal radiation from Eu, Al doped SiO 2 (SiO 2 :Eu, Al) glass fiber have been studied for a fiber-optic thermometer application. Photoluminescence (PL) peaking at λ =433, 485 and 617 nm is clearly observed from SiO 2 :Eu, Al glass with UV excitation ( λ =365 nm). Peak intensity of PL decreases with temperature form 300 to 1000 K. Visible light thermal radiation peaking at λ =660 nm is also observed from SiO 2 :Eu, Al glass above 1000 K. Peak intensity of visible light thermal radiation increases exponentially with temperature. Temperature can be measured based on temperature dependences of PL (below 1100 K) and visible light thermal radiation (above 1000 K) using SiO 2 :Eu, Al glass fiber. The hybridization of fluorescence thermometry (below 1000 K) and thermal radiation thermometry (fiber-optic pyrometer, above 1000 K) using SiO 2 :Eu, Al glass fiber is thought to extend the temperature range of a fiber-optic thermometer.

Photoluminescence spectrum, trap depths, and densities of trapped carriers of CaAl2O4:Eu phosphor crystals doped with rare-earth elements were studied using the thermally stimulated luminescence technique. Trap depths and densities of the specimens vary with rare-earth elements doped as the auxiliary activators. Tm and Nd are found to be effective for the strong afterglow phosphorescence peaking at λ = 442 nm for several hours after the excitation. CaAl2O4:Eu phosphor crystals doped with Nd and Tm include high density of carriers trapped at E = 0.59 and 0.52 eV, respectively.

Optical scattering spectra and angular distribution of scattering intensities were evaluated using commercially available tomato juice for a non-destructive quality control. A halogen lamp, a red LED and NIR LEDs (λ = 850 nm and λ = 940 nm) can be used as the incident light for scattering evaluations of tomato because incident light with wavelengths shorter than 550 nm is absorbed by pigments in tomato. Scattering intensities and their angular distributions are found to depend on the sugar concentrations of tomato juice. The scattering intensities vary linearly with the sugar concentrations of the specimens irradiated with a halogen lamp, a red LED or NIR LEDs (λ = 850 nm and λ = 940 nm). Gradient of calibration lines, G, between the sugar concentrations and the scattering intensities varies with the scattering angles and the wavelength of light irradiated. G is large negative value with large scattering angles such as a back scattering configuration. While, G is small positive value with small scattering angles such as a forward scattering configuration.

Equipment for the non-destructive evaluations of a tomato has been developed based on the scattering spectra, the angular distributions of the scattering intensities, and the scattering images from the specimens. The sugar concentrations of tomato can be estimated optically based on the scattering intensities using a halogen lamp, a white light-emitting diode (white LED), a yellow LED, a red LED, and near infrared LEDs (λ = 850 nm and 940 nm) as the incident lights. The scattering intensity is found to vary linearly with sugar concentrations of tomato with any wavelengths at which the scattering light can be observed. The gradient of calibration lines of the sugar concentrations against the scattering intensities varies with scattering angles, θ. Evaluations at around θ = 160° are found to be suitable because of the large gradient and good linearity with the correlation coefficient, R, close to 1.

Thermo-sensor characteristics of Cr doped YAlO3 composite with silicone resin have been evaluated based on the temperature dependence of photoluminescence intensity from the specimens. Photoluminescence (PL) peaking at wavelengths, λ = 725, 732 and 748 nm are observed from the composite sensor with an excitation by green colored LED at λ = 536 nm. PL peak intensities and peak intensity ratio varies sensitively with temperature. Silicone composite sensor with 50 wt% of 0.2 at% Cr doped YAlO3 powders is found to be useful sensor for fluorescence thermometer, because of the large temperature coefficient and good repeatability of PL intensity ratio.

Luminescence properties of Mn doped MgAl2O4 crystals connected with the Si PIN photodiode (PD) have been evaluated for X-ray detector applications. Mn doped MgAl2O4 crystals emit green colored luminescence peaking at around λ = 520 nm with CuKα irradiation. The intensity of the output signal from Si PD increases linearly with the X-ray intensity of CuKα generated with the X-ray tube at a current from 2 mA to 40 mA. The intensity of the X-ray excited luminescence is strongest in the specimen with 3.0 mol. % Mn. Afterglow luminescence is weak in the specimen with 2.0 mol. % Mn. Mn doped MgAl2O4 crystals connected with the Si PD is considered to be a useful X-ray detector.

Rare-earth aluminate crystals have chemical and thermal stability, which are advantage for the sensor materials of a fiber-optic fluorescence thermometer. Among many rare-earth aluminate crystals, rare-earth garnet, Y 3 Al 5 O 12 , doped with Cr 2 O 3 (Cr-doped YAG), is found to be useful as the sensor materials for fluorescence thermometer. Fluorescence lifetime of Cr-doped YAG crystal decreases from 2 ms to 0.1 ms as the temperature increases from 273 K to 900 K. Moreover, thermal radiation from Cr-doped YAG crystal can be observed from 800 K using Si photo-detector. The fiber-optic thermometer with extremely wide temperature range is considered to be produced by the combination of the temperature dependence of the fluorescence lifetime and the thermal radiation from Cr-doped YAG crystal.

BaAl 2 O 4 :Eu,Dy (BAO) films have been fabricated on Si substrate by laser ablation, and their fundamental optical property and afterglow characteristics are discussed in comparison with the SrAl 2 O 4 :Eu,Dy (SAO) films. The intense green emission near 500 nm that originates from 5d to 4f transition in Eu 2+ ions was clearly observed from the BAO films. This photoluminescence peak was at a shorter wavelength than that of the SAO films (λ=520 nm). The afterglow intensity from the BAO films disappeared within a few minutes whereas that of the SAO films lasts over 20 min. The hole-trap depth (E t ) created by Dy as the auxiliary activators, which strongly affects the afterglow characteristics, was estimated on the basis of the thermally stimulated luminescence (TSL) result. The TSL glow curve for BAO films showed two broad peaks at 320 K and 450 K. The calculated E t for each peak was 0.2 eV (for the 320 K peak) and 1.2 eV (for the 450 K peak). On the other hand, E t =0.5 eV was obtained from the SAO films. The hole-trap depths of the BAO film are either too shallow or too deep to affect the afterglow characteristics at room temperature.

Terbium ion (Tb 3+ ) doped silica glass (Tb:SiO 2 ) and yttrium aluminum garnet crystals (Tb:YAG) have been fabricated for the applications in fiber-optic thermometers based on the temperature dependence of the photoluminescence (PL) spectrum. Several PL peaks at 490, 540, 585, 625 nm were observed from both Tb doped phosphors. In Tb:YAG crystal, the PL peaks were split into two or three small peaks due to the Stark effect. Temperature dependence of PL spectra from Tb:SiO 2 glass and Tb:YAG crystal was evaluated over a temperature range from 300 to 1200 K. In the Tb:SiO 2 glass, the peak PL intensity varied greatly with temperature. The shape of the PL spectrum from Tb:YAG crystal varied with temperature because the resolution of the split in the peak PL decreased with temperature. The intensity ratio between splitting PL peaks, therefore, varied with temperature. From these results, Tb:SiO 2 glass and Tb:YAG crystals are considered to be a useful sensor head materials for high temperature measurement using temperature dependence of PL intensity.

Long afterglow phosphorescent SrAl 2 O 4 :Eu,Dy thin films have been fabricated on Si substrate by laser ablation. The thin film phosphors show the intense green emission near 520 nm, and additional emissions near 390 nm and near 450 nm that are originating from 5d–4f transition in Eu 2+ Eu 2 + ions doped in the thin films. The afterglow intensity at 520 nm of the thin film phosphors was detected over 20 min later, after excitation was removed. The afterglow characteristics is almost the same between in the SrAl 2 O 4 :Eu,Dy thin film phosphors and the SrAl 2 O 4 :Eu,Dy bulk phosphors. Then, the long afterglow characteristics are interpreted by the hole trapping due to the Dy 3+ Dy 3 + ions added as the auxiliary activator doped into the SrAl 2 O 4 thin films.

Temperature dependence of photoluminescence (PL) peaking at wavelength of λ = 440 nm from FZ grown CaAl 2 O 4 ; Eu, Dy phosphor crystal is evaluated for a fiber-optic thermometer application. The PL lifetime from the specimens decreases greatly from 11.24 to 1.17 ms as the temperature increases from 305 to 458 K. The temperature coefficient of PL lifetime, - 0.17 ms / K , in the narrow temperature range from 305 to 345 K is larger than that of ruby (Cr doped Al 2 O 3 ) whose PL lifetime is 4 ms and temperature coefficient is - 0.169 ms / K . The large temperature coefficient of PL lifetime of CaAl 2 O 4 : Eu, Dy phosphor crystal is due to the trap levels generated by Dy doping.

A fibre-optic thermometer using newly developed phosphor sensor materials is described. A highly sensitive fibre-optic fluorescence thermometer is developed using chromium ion (Cr3+) doped phosphor crystals with a longer lifetime than that of conventional ruby sensors. Long fluorescent europium doped strontium aluminate phosphors co-doped with various auxiliary activators (SrAl2O4:Eu2+, Ln3+, Ln = Y, La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu), were also grown and evaluated. In the fibre-optic thermometer using Cr3+ doped phosphor, PL lifetime decreased at temperatures ranging from 270 K to 750 K. The sensitivity of the fibre-optic thermometer varies with the host materials of Cr3+ ions. In the fibre-optic thermometer using SrAl2O4:Eu2+, Ln3+ doped phosphor, the value and lifetime of afterglow phosphorescence from the SrAl2O4:Eu2+, Ln3+ phosphors varied greatly in the narrow temperature region because the afterglow phosphorescence was dominated by thermal excitation of trapped carriers. Since the trap depth and the trap density depend on auxiliary activator elements, the sensitivity and temperature range of the fibre-optic thermometer using SrAl2O4:Eu2+, Ln3+ phosphors varied with auxiliary activator elements of SrAl2O4:Eu2+, Ln3+ phosphors.

The fiber-optic thermometer probe, in which the sapphire fiber was connected mechanically with the ruby sensor head, has been fabricated and the performances of the probes are evaluated as compared with those using the silica fiber. The value of photoluminescence (PL) lifetime and its temperature coefficients for the ruby sensor head with sapphire fiber (t=3.9 ms and −9.9 μs/K) were slightly different from those using the silica fiber (τ=4.2 ms and −10.9 μs/K), even if the same ruby sensor head was used. These differences are found to be caused by the background PL due to residual impurities and/or defects in the sapphire fibers, which vary with the growth techniques of the fibers. The influence of the PL from the sapphire fiber on the temperature measurements can be reduced successfully using a modified lifetime calculation based on the curve fitting of the PL decay with double exponential equation. By using a modified lifetime calculation, the ruby sensor head with sapphire fiber can be used in the temperature measurement ranging from 270 to 670 K with ±1.5 K accuracy.

The chromium doped spinel crystals, MgAl2O4:Cr3+, have been grown using floating zone technique and its application for the fiber-optic thermometer is discussed on the basis of the temperature dependence of the fluorescence lifetime. Lifetimes of the spinel crystals (τ=10 ms), which decrease with temperature, were about 3 times larger than that of the ruby crystals (τ=4 ms) at room temperature. Temperature coefficients of the photoluminescence (PL) lifetimes for spinel crystals (37 μs/K) are also 3 times longer than that for the ruby crystals (10 μs/K). The spinel crystals are potentially useful sensor probes for the fiber-optic thermometer, which have an advantage of high sensitivity due to long PL lifetime and large temperature coefficient.

This paper describes a fiber optic oxygen sensor using fluorescence and its application to clinical examinations. The quenching ratio of fluorecence is proportional to oxygen partial pressure by the Stern-Volmer's formula by which the oxygen concentration is possible to estimate from measured emission intensity. We have fabricated a microscopic luminous probe using Solvent Green 5 doped plastic optical fiber coupler. A microscopic luminous probe was experimentally investigated as an oxygen sensor in visible light. In addition, we have clarified various characteristics of this sensor.

Visible light photoluminescence (PL) peaking at around λ = 460 nm is observed from cereals, such as rice, wheat, barley, millet, flour, corn starch, peanut, under illumination of ultra-violet light at λ = 365 nm. Peak intensity of PL varies with variety and source of the specimens. Distribution of PL intensity over two dimensional PL image of a cereal with a single variety and a single source is found to be fitted with a Gaussian curve. Visible light PL is suggested to be potentially useful technique for the non-destructive and quick evaluation of the cereals and other starchy products.

This paper describes a fiber-optic oxygen sensor using fluorescence and its application to clinical examinations. The quenching ratio of fluorescence is proportional to oxygen partial pressure by Stern-Volmer's formula in which oxygen concentration is estimated from measured emission intensity. We fabricated a microscopic luminous probe using a Solvent Green 5 doped plastic optical fiber coupler. The probe was studied as an oxygen sensor in visible light. We also clarified sensor characteristics.

Cr-doped YAlO3 phosphor crystals have been grown and characterized for applications in fiber-optic thermometers based on the temperature dependence of the photoluminescence (PL) lifetime. PL peaking at λ=735 nm is observed from the crystals following an excitation by a light-emitting diode at λ=520 nm. Long PL lifetime (τ=43.14 ms) is observed from Cr-doped YAlO3 at room temperature as compared with those of ruby (τ=4.2 ms) and spinel (τ=8.0 ms). The temperature coefficient (−0.075 ms/K) of Cr-doped YAlO3 is also larger than those of ruby (−0.010 ms/K) or spinel (−0.037 ms/K). YAlO3 is considered to be a sensitive sensor head material for fiber-optics thermometers.

Ruby single crystals have been grown successfully from the melt droplet on the sapphire crystal fibers as the sensor head directly coupled with optical fiber for the thermometer applications using fluorescence decay. In this fabrication process, droplets of slurry of ruby powders are formed on the end of the sapphire crystal fiber and are dried, sintered, and then melted and solidified in a floating-zone furnace. The photoluminescence (PL) lifetime of the ruby sensor head varies from τ=3.8 to 2.5 ms with the Cr3+ concentrations from 0.07 to 1.0 at. %. The ruby crystal with a Cr3+ concentration of 0.35 at. % is found to be the most suitable sensor head having the longest PL lifetime. The temperature coefficient of the fiber-optic thermometer equipment using the directly coupled ruby sensor head with a Cr3+ concentration of 0.35 at. % is −12.4 μs/K.

Photoluminescence (PL) imaging is curried out using Cr doped spinel sensors at various temperatures for 2-dimensional fluorescence thermometer application. PL images can be clearly observed using a CCD camera and UV, green and/or blue LED illuminations. Brightness of PL images from Cr doped spinel sensor decrease with temperature up to 250degC. PL imaging is suggested to be useful for 2-dimensional fluorescence thermometer applications.

Temperature monitoring is essentially important for stable control of fabrication processes. In order to develop a convenient 2-dimensional temperature monitoring system using a thermo-paint, photoluminescence (PL) images are observed from the luminous paints at various temperatures. Commercially available and in-house modified luminous paints are evaluated for improving temperature sensitivity and stability of the thermo-paints. Temperature dependences of PL images from various luminous paints are reported for developing temperature monitoring procedure using a thermo-paint.

This paper describes an optrode sensor for chemical and physical measurement and its application to industrial examinations. Among many king of optrode sensors, we have fabricated a temperature, oxygen and pH sensor and characteristics of which was experimentally investigated. Our experimental data shows the optrode sensor for chemical and physical measurement has singular capability as compared with a conventional sensor such as an electrode sensor.

Spinel crystals (Cr doped MgAl2O4) with various Cr2O3 and MgO concentrations are grown using floating zone technique for fluorescence thermometer application. Temperature dependence of photoluminescence (PL) intensity is evaluated using spinel crystal and/or composite of spinel with silicone resin. PL intensity from spinel crystal and composite decreases linearly with temperature. Spenel crystal and composite are useful as sensor materials in fluorescence thermometer.

A possibility of low temperature measurement using fluorescence thermometry was examined. Temperature dependence of fluorescence lifetime applied to low temperature measurement. Chromium ion doped sapphire crystal (ruby) is known as a suitable sensor material for temperature measurement. Fluorescence thermometer using the ruby which is modified for temperature measurement has been fabricated. From this research, ruby crystal is found to be useful as the sensor head for fluorescence thermometer. In addition, the ruby crystal is potentially useful material for the sensor head crystals to measure low temperature below 273 K.

A TiO2:Nd formed on Si(100) substrate by laser ablation. The TiO2:Nd shows IR emissions at room temperature. The superconducting magnet was used for applied of a magnetic field. Magnetic field intensity was changed from 0.0 T (Tesla) to 8.0 T with PL measurement at room temperature. The sharp intense PL peak at 913.5 nm, 933.3 nm, 954.6 nm, 1093.7 nm and 1382.7 nm originating from the intra-4f shell transition in Nd3+ ions was observed. The spectrum form change was according to the Zeeman effect with the rise of magnetic field intensity.

Photoluminescence (PL) images from Ti doped sapphire (Ti doped Al2O3) crystals are observed for 2-dimensional fluorescence thermometer applications. Red colored bright PL images can be observed clearly from Ti doped sapphire sensor using a CCD camera under blue LED illumination. Intensity of red signal of the PL image decreases linearly with temperature of the sensor. Ti doped sapphire sensor is found to be useful for fluorescence temperature measurement using PL imaging technique.

Thermal imaging technique is useful for detecting 2-dimensional spatial distribution and temporal variation of temperature. Thermal images of foods during the cooking process and/or pulse heating process are observed for evaluating the quality of foods in the volume fabrications. Inhomogeneous temperature distribution of a pancake can be observed during the baking process. Water concentration of flour can be measured from temporal evaluation of thermal images.

Red colored photoluminescence (PL) images have been observed from Cr doped garnet, Y3Al5O12 (YAG) sensor using a CCD camera system. PL image from YAG sensor increases linearly with temperature from 25 to 250degC. Temperature can be measured using PL image from Cr doped YAG sensor. Image processing techniques, such as line scanning, histogram and integration of brightness are effective for two-dimensional fluorescence thermometer application.

Temperature response of soil specimens, which is one of major contains of volcanic ash soil, are measured by pulse heating technique. Water contents of various specimens are evaluated from temperature response of specimens using two-dimensional radiation thermometer and thermocouples. Infrared radiation thermometry is a non-contact and non-destructive technique to detect the properties or internal conditions of a material from the temperature variation of surface. Decay lifetime of surface temperature is calculated with exponential curve composed from two decay components. Two-dimensional distribution of faster component dasiatau1psila is evaluated with using thermal images. Two-dimensional distribution of water contents can be evaluated using lifetime of faster decay components calculated from thermal imaging. Dynamic characteristics of soil are suggested to be useful for evaluation of soil for agriculture.

Fluorescence thermometer using photoluminescence (PL) images from sensor is studied for two-dimensional and non-contact temperature measurement. Visible light PL images can be observed clearly from fluorescence thermo-sensors using CCD camera with green, blue and/or UV excitation. Temperature can be measured based on temperature dependence of brightness of the PL images. Video images processing technique is found to be effective for fluorescence temperature measurement based on PL images from the crystal and composite sensors.

Optical pH measurement method based on the color change from the organic dye film was examined. Six pH indicators were selected for wide pH measurement range. Absorption spectra of the visible light were evaluated to six pH indicators. Moreover, pH valuation of the absorption spectra was evaluated for the optical pH measurement method application.

Various sensor materials are developed and evaluated for fluorescence thermometer applications. Sensor materials such as ruby (Al2O3), YALO (YAlO3), YAG (Y3AI5O12), rare-earth ultra-phosphates, long afterglow phosphors, starch and organic pigments are evaluated based on temperature dependences of photoluminescence (PL) lifetime and/or PL intensity. Characteristics of these sensor materials are reported for fluorescence thermometer application.

Two-dimensional photoluminescence (PL) image from sensor material is evaluated for fluorescence thermometer application. Two dimensional PL image is observed using CCD video camera under blue and/or UV LED illuminations. Red colored PL image can be observed from ruby sensor under illumination of blue LED. Brightness of red signal of PL image from ruby sensor varies linearly with temperature from 20 to 100degC Temperature can be measured based on brightness of PL images from fluorescence thermo-sensors. Video images processing technique (line scanning of intensity, histogram and integration of signal intensity) is found to be effective for fluorescence temperature measurement using phosphor sensors.