The absolute spectral responsivity of inversion layer type silicon photodiodes in the visible region has been determined by the self-calibration measurements on four wavelengths and interpolation. Using the calibrated photodiodes in combination with a V (λ) filter and a precision aperture, a photometric standard detector has been constructed. The spectral transmittance of the filter was measured by a method which can eliminate, in principle, the errors caused by the interreflections between the filter and the photodiode surface, and the errors caused by the spatial non-uniformity of the transmittance of the filter. The calibrated detector was compared with a working luminous intensity standard lamp supplied from ETL (Electrotechnical Laboratory) of Japan, and also with luminous intensity standard lamps maintained at NIST of the U. S. The luminous intensity measured by the detector agreed with the values of ETL and NIST within a 0.5% difference.
Recently, the heating technology by far infrared radiation has been being interested in various fields such as industry, agriculture, medical engineering and so on. This is mainly because of its excellent heating efficiency. This paper describes far infrared radiating properties of natural zeolite. The effect of the sintering temperature and kinds of compositions on far infrared radiating properties of natural zeolite are investigated and discussed. The spectral emissivity of natural zeolite was measured at the wavelength range from 2.5 μm to 25 μm, at the surface temperature of 400°C. The spectral emissivity of natural zeolite was compared with those of other oxide-ceramics. As a results, it was found that the spectral emissivity of the natural zeolite was higher, especially in the wavelength range of 2.5 μm to 5μm. The sintering temperature influences on the spectral emissivity of natural zeolite. The emissivity below the wavelength of 5μm increases with increasing in the sintering temperature. The spectral emissivity in at far infrared region of the mixed oxide-ceramics was found to be corresponding to each components of mono oxide-ceramics.
A formula for luminance distribution on the clear cloudless sky and a formula for total horizontal illuminance from that sky are proposed based on a scattering theory. The clear sky light consists of the scattered light of the direct sunlight and that of the reflected light from the ground surface. And the main scattered light in the clear sky is the lst-order scattered light of the direct sunlight, but its higher order scattered light than or equal to the 2nd-order and the scattered light of the reflected light from the ground surface are considerably included in the clear sky light and they have effect on the variation of clear sky light, respectively. In the proposed formulas, these effects are estimated from the result of a theoretical analysis. In the conventional formulas for the clear sky luminance distrinution which are derived based on observation, however, these effects are not done because of difficulties of the estimation by means of measurements. Therefore the luminance distributions from the proposed formula approximate more closely to measured data under the clear sky than the conventinal formulas. And the proposed formula for total horizontal illuminance from the clear sky is applicable not only to the clear sky but to the overcast sky because the scattering characteristics of cloud is equivalent to those tof the clear skywhere aerosole is included quite densely.
A method which was able to measure quickly and accurately adhesion quantity of agricultural chemicals was developed. Fluorescent materials were used to detect agricultural chemicals in this method. Performance of an agricultural chemicals sprayer has been estimated by a conventional visual inspection or a chemical analysis until now. This method made more quickly and accurately to estimate that performance. Fluorescent material water solution of 300-500 times the weight was sprayed by the sprayer. An amount of fluorescent material stained on the samples (plants) was quantitatively measured by a fluorescent detector developed for this method. The summaries are as follows. (1) The fluorescent materials were water-soluble organic pigments. (2) To avoid the plant pigment fluorescent wavelength, the peak radiation wavelength of the fluorescent materials which was longer than 550 nm was selected. (3) The wavelength region of exiting radiation for fluorescence was the range of 320-400 nm. and the black light fluorescentlamp as the exiting source was operated with 300 Hz. (4) To detect a weak fluorescence, a lock-in detection technique, which was synchronous to the lamp operatiog frequency, was used. (5) Measuring the spray state of agricultural chemicals in field by using this method, the results agreed with those of the conventional method.