C. Nakayama

Thermal-imaging of foods in heating process

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.

Development of Sensor Materials in Fluorescence Thermometer

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.

Fluorescence Thermometer Based on 2-Dimensional Photoluminescence Imaging

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.

Fluorescence sensor using two-dimensional phosphor array

Two-dimensional sensor array composed of various phosphors has been evaluated for fluorescence thermometer application. In a matrix sensor, 3times3 composite phosphors are separately located on 10times10 mm2 polymer substrate. Long afterglow phosphors, starch and ruby composites are used as phosphor of sensor array. Photoluminescence (PL) from phosphor composites on matrix sensor are evaluated using a fiber spectrometer. Two dimensional observation of PL from matrix sensor is also observed using CCD camera and UV illumination. Images processing technique is found to be effective for two dimensional evaluation of PL from the sensor array.

Two-dimensional sensor array for fluorescence thermometer

Two-dimensional sensor array composed of various phosphors has been evaluated for fluorescence thermometer application. In a matrix sensor, 3times3 composite phosphors are separately located on 10times10 mm2 square substrate. Two dimensional observation of photoluminescence (PL) from array sensor is curried out using CCD camera under UV illumination. Brightness of phosphors in the PL image varies linearly with temperature. Images processing technique (line scanning of intensity) is found to be effective for evaluation of PL from the sensor array.

Two-dimensional evaluation of soil property based on thermal imaging

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.

The optical magnetic sensor using Nd doped YAG crystals

The magnetic field dependence of photo luminescence (PL) peak split and peak intensity rate from Nd doped YAG crystal was studied for the optical-magnetic sensor application. Photoluminescence peaking at the wavelength from 800 nm to 1400 nm are observed in Nd doped YAG crystal at room temperature. The feature of these PL peaks split with magnetic field. Peak intensity rate and Peak split of PL from Nd doped YAG crystal linearly with the magnetic field increasing from 0.0 T to 8.0 T at room temperature. Fluorescence optical magnetic sensor system using fluorescence sensor crystal enables non-contact magnetic field measurements.

Two dimensional evaluation of soil property for agriculture

Temperature response of soil is measured using a radiation thermometry and thermocouples with pulse heating technique for agriculture application. Temperature response of various water contents of the soils is evaluated using radiation thermometer and pulse heating technique. The infrared radiation is a non-contact and non-destructive technique to detect the properties or interior conditions of a material from its temperature changes on the surface. The thermal property could calculate based on the phase lag of the temperature by thermocouples. Decay lifetime of surface temperature as soil is calculated using exponential curve with two decay component. Decay lifetime of varies with components & water contents of soil. Dynamic thermal characteristics of soil are suggested to be useful for evaluation of agriculture.

Non-contact water content measurement of soil based on thermal imaging

The water contents of soil must be monitored and controlled for glowing plants in the field, because measuring of water content is one of most important technique for the agriculture. The temperature response of soil is measured by using thermo-viewer and infrared radiation thermometry, which are non-contact to soil. It is suggested to be useful for thermal characterization of soil. Thermal response of the soil may be affected by properties of soil surface such as, water content, thermal diffusion and thermal transfer from specimens. Dynamic thermal characteristics of soil are suggested to be useful for evaluation of soil agriculture.

The optical magnetic sensor using Nd doped TiO 2 thin films

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.