Patent RU-2241220-C2 (RU)
Inventor: PEN KOVSKIJ A I
IPC: G01N33/14
Filed: 2001-12-13
Granted: 2004-11-27
Abstract: FIELD: vodka industry. 
     SUBSTANCE: method includes letting vodka to be analyzed through differential dish of refraction meter, made in form of two protective glass windows mounted in parallel to each other and plates mounted between windows with a slant. The latter form a system of adjacent prisms of standard vodka and subject vodka. Dish is lit through by a parallel light beam formed by collimator with a monochromatic light source, slit, mounted in objective focus. After dish deflected light beam is sent to objective, which builds an image of collimator slit on sensitive layer of matrix multi-element photo-detector. From value of deviation of image of slit ΔX relatively to zero position X 0 a difference of refraction coefficients between standard and subject vodka is derived,   target vodka refraction coefficient n'       Dx          =  n Do  + Δn D  and from found n'       Dx          a  volumetric share of ethyl spirits A 0 % is determined. Mixing of image of slit ΔX at photo-detector is fixed at position of its middle, for that coordinates of front X 1  and back X 2  limits of slit image are recorded, coordinate of image middle point is found  , temperature correction is determined from formula  , also determined is correction caused by effect from admixtures by concentration C % of sugars Δn Ds  = 0.00142·C%, refraction coefficient of subject vodka is determined which matches temperature t=20°C without sugar admixtures  , and volumetric share of spirits in vodka is calculated from formula    
      where ΔX - value of slit image displacement, X 0  - zero position of slit image, Δn D  - refraction coefficients difference, n Do  - standard vodka refraction coefficient, n Dx  - subject vodka refraction coefficient, f 1  - objective focus distance, θ - refraction angle of adjacent dish prisms, n'       Dx        - target vodka refraction coefficient, A 0 % - volumetric share of ethyl spirits in vodka, X 1  - front slit image limit coordinate, X 2  - back slit image limit coordinate, X t  - slit image middle point coordinate, Δn       t   D        - refraction coefficient temperature correction, t - temperature °C, C% - concentration of sugars added to vodka, Δn Ds  - refraction coefficient correction, caused by sugar admixtures in vodka, N D  = (n D -1.350000)·32 - auxiliary variable. Device has body in form of hermetic cover and monochromatic light source, slit, collimating objective, differential dish in form of system of adjacent prisms of standard and subject vodkas, main cross-section of which is perpendicular to slit, deflecting device with two deflecting surfaces at 90° angle to each other in form of prism, main cross-section of which is parallel to main cross-section of dish prisms system, second objective, on focal plane of which a matrix multi-element photo-detector is mounted connected to information processing device, which are serially mounted. Dish is fixed outside hermetic cover of body. Non-removable portion of dish is fixed on body through heat-insulating packing and is provided with channels for screwing in end pieces of flexible pipes, connecting device to main pipeline. Removable portion of dish is made in form of cap. Protective windows of both portions of dish are made in form of glass plates plane-parallel to each other, common for falling and reflected from prism light beams. Hollow for standard vodka is made in form of removable insert, protective windows of which form a rhombus in main cross-section, and which is placed inside the dish in such a way, that it is washed by subject vodka on all sides. Whole dish is covered by heat-insulating cover. Between light source and slit a condenser is mounted in form of cylindrical lens with forming line of cylinder being parallel to slit. In body of device an inlet device is mounted for connecting flow polarimeter providing information about value of sugar admixtures in subject vodka. 
     EFFECT: higher precision of analysis. 
     2 cl, 5 dwg