Abstract: An excitation beam generated from a light source is separated into a measuring beam and a reference beam by an optical path adjusting optical system including a beam splitter, so that the measuring beam is applied to a sample in a cell. Raman scattering light which is generated from the sample is detected by a spectral detector including a spectroscope through a scattering light path adjusting optical system and a wavelength selector. In a spectrum obtained by the spectral detector, a peak of Raman scattering in which wavenumber shift from the wavelength of the excitation beam is present at 800 to 920 cm.sup.-1 is employed to make quantitative measurement of hydrogen peroxide. Hydrogen peroxide contained in an aqueous solution can be simply quantitatively analyzed through optical analysis means.

Abstract: In order to quantitatively measure an Amadori compound by a simple optical method utilizing light scattering, a sample containing an Amadori compound which is stored in a cell is irradiated with excitation light from an He--Ne laser unit so that scattered light from the sample is received and separated into its spectral components for obtaining a light scattering spectrum, and a light scattering peak existing at 820 to 840 cm.sup.-1, 1655 to 1660 cm.sup.-1, 2000 to 2020 cm.sup.-1, 2080 to 2100 cm.sup.-1, 2460 to 2470 cm.sup.-1 or 2530 to 2600 cm.sup.-1 in shift wavenumber with respect to the excitation wavelength in the light scattering spectrum is detected by a detector. The saccharide concentration or the saccharification ratio of the Amadori compound is measured by a calibration curve through the peak intensity or the peak integral value of the light scattering peak.

Abstract: A plastic material, controlled at a desired temperature, is fed on an upstream side of a gap between a pair of rotating forming rolls arrayed almost in parallel and controlled at a desired temperature from a device for feeding the plastic material. The plastic material is pressed and formed into a sheet by the forming rolls therebetween while forming a bank or an accumulation of the plastic material on an upstream side of the gap of the forming rolls and is carried out on a downstream side of the gap. The bank quantity monitoring is performed by measuring a temperature of the sheet carried out through the gap of the forming rolls and estimating the quantity of the bank in accordance with measured temperature information. The sheet formation is performed by measuring a temperature of the sheet carried out through the gap of the forming rolls and controlling various forming conditions according to a measured temperature information.

Abstract: A plastic material, controlled at a desired temperature, is fed on an upstream side of a gap between a pair of rotating forming rolls arrayed almost in parallel and controlled at a desired temperature from a flat die connected to an extruding machine and having a slit outflow portion. The plastic material is pressed and formed into a sheet by the forming rolls therebetween while forming a bank or an accumulation of the plastic material on an upstream side of the gap of the forming rolls and is carried out on a downstream side of the gap. The bank quantity monitoring is performed by measuring a temperature of the sheet carried out through the gap of the forming rolls and estimating the quantity of the bank in accordance with measured temperature information. The sheet formation is performed by measuring a temperature of the sheet carried out through the gap of the forming rolls and controlling various forming conditions according to a measured temperature information.