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Measurements of the refractive index, its temperature dependence, and the optical transmission of black liquors produced during sulfate pulping are reported for soluble solid residue concentrations up to k ≅ 60 %. The design features of a commercial refractometer for monitoring the concentration of black liquor are examined briefly. A procedure is proposed for laboratory calibration of commercial sensors that employs black liquor solutions in highly refractive organic liquids as reference samples.

Within Kubelka–Munk theory using the Lorenz relations, we have determined the correlation between the optical diffuse reflectance spectra R(λ) of cellulose pulp in the visible range (380–760 nm) and ultraviolet absorption (λ = 200–400 nm) of aqueous solutions containing residual lignins. The data obtained can be used to monitor and predict the results of digestion and bleach plants in the paper and pulp industry.

We have studied diffuse reflectance in the spectral range λ = 380–760 nm of sulfate cellulose pulp with initial hardness G = 30–70 after it was treated with a chlorine-containing bleaching agent with active chlorine concentration C = 0%–10% for different time intervals. We determined the general behavior and basic features of the concentration and time dependences of the brightness B and the diffuse reflectance spectral ratio (R437/R650)⋅100% at λ = 457 nm and 650 nm. Based on the data obtained, we propose an optimal algorithm for using optical spectral technologies for metered addition of chlorine-containing bleaching agents.

The paper deals with the application of spectrophotometric method and the sensor for determination of contaminating hydrocarbon impurity presence in waste water. The sensor is designed on the basis of modern element base. For measurement accuracy increase it has computer processing of analysis results for the absorption spectra of liquid (water) media in the ultraviolet wavelength range. The proposed sensor and computer program enabled the study of hydrocarbon impurity presence in the water that is an important factor for continuous monitoring of the environment. The absorption spectra of gasoline, diesel fuel, synthetic motor oil, fuel oil, natural oil are given as the most frequently present as impurities in the water, measured on an automated spectrophotometric sensor model. The use of modern small-sized elements makes it possible to design a small-sized highly sensitive sensor for express analysis of the water quality.

The paper considers the possibility of a flat light field creation (light raster) of a large size by laser scanning at a distance of several tens of meters with angular sizes equal to 20º×4º. It is shown that the filling of such size raster by light is possible with the use of a single laser. The uniformity of light raster illumination is achieved by choice of parameters for collimating and scanning optical systems, the speed of light spot movement on the line and frame, turnover frequency of frames, spot light overlap factor. We present findings that give the possibility to obtain relatively uniform raster illumination at laser scanning and the filling of large size raster with low power laser light from the radiation source.

Subject of Research. The paper presents the results of measurements of refractometric properties (refractive index n, its temperature factor dn/dt) and the ultraviolet spectral absorption in carbonic acid diamide aqueous solutions (carbamide) depending on solid residue mass fraction md = 0-50 % and on temperaturet = 10-70 °C.Method of Research. Laboratory methods ofliquid-phase medium refractometry and ultraviolet spectrophotometry were applied for the research. We carried out computational modeling of electronic states spectrum for the carbonic acid diamide molecule and theoretical calculation of the fundamental electronic absorption of the molecule in the ultraviolet wavelenght region.Main Results. We have established that the solution concentration md has a nonlinear character and may be represented by the quadratic polynomial with the error Δn= ± 0,0005. We have shown the refractive indexdependence on temperature n(t) changes in linear fashion att = 10-70 °C.At that, the inclination of lines n(t) increases at the increase of md; so, the temperature factor dn/dt may be approximated by the quadratic polynomial. Transmission spectra of solutions in the spectral region λ= 225-760 nm have no special features except for the sharp edge in the short-wavelength region; the fundamental electronic absorptionis responsible for it. We have established that dispersion dependences of the refraction index n(λ;md) in aqueous solutions of carbamide at λ= 360-760 nm and at md = 0-50 % may be calculated with the satisfactory error without additional adjustable parameters from the ultraviolet absorption data in terms of the one-dimentional oscillator Lorentz model.PracticalRelevance. Representedmeasurements of carbonic acid diamide aqueous solutions optical properties may be applied for the adjustment and calibration of commercial refractometers at processing lines of the AdBlue reagent manufacture for the selective catalytic reduction (SCR) of motor transport exhaust gases.

Design features and basic technical-performance characteristics of laboratory spectrophotometer for visible spectral region (λ = 380-760 nm) are considered. Results of device approbation are given, as well as examples of its application for photo-optical bleaching, toning and coloring technologies control of paper.

The paper deals with the application of spectrophotometric method and the sensor for determination of contaminating hydrocarbon impurity presence in waste water. The sensor is designed on the basis of modern element base. For measurement accuracy increase it has computer processing of analysis results for the absorption spectra of liquid (water) media in the ultraviolet wavelength range. The proposed sensor and computer program enabled the study of hydrocarbon impurity presence in the water that is an important factor for continuous monitoring of the environment. The absorption spectra of gasoline, diesel fuel, synthetic motor oil, fuel oil, natural oil are given as the most frequently present as impurities in the water, measured on an automated spectrophotometric sensor model. The use of modern small-sized elements makes it possible to design a small-sized highly sensitive sensor for express analysis of the water quality.

The article deals with optical methods, control and diagnostics means of bleaching works in the pulp and paper industry using chlorinated whitens. Results of laboratory studies in visible region of wavelengths of cellulose diffuse reflectance R and parameter of whiteness B against the expenditure of chlorinated whiten and continuance of bleaching process are represented. Spectral data of diffuse reflectance are compared with the ultraviolet absorption in aqueous solutions of residual lignins. Algorithms of optical spectral technologies application for optimization of pulp bleaching works are substantiated. Results of industrial tests of optical spectral sensor of whiteness in Kotlas Pulp and Paper Mill bleaching manufacture are represented.

The paper considers the possibility of a flat light field creation (light raster) of a large size by laser scanning at a distance of several tens of meters with angular sizes equal to 20º×4º. It is shown that the filling of such size raster by light is possible with the use of a single laser. The uniformity of light raster illumination is achieved by choice of parameters for collimating and scanning optical systems, the speed of light spot movement on the line and frame, turnover frequency of frames, spot light overlap factor. We present findings that give the possibility to obtain relatively uniform raster illumination at laser scanning and the filling of large size raster with low power laser light from the radiation source.