T1 = 171.9178
WEIGHT OF PYCNOMETER FULL OF WINE AT 18* C : P2 = 169.2799
VARIATION IN THE BUOYANCY OF AIR : DT = 171.9178 - 171.9160 = + 0.0018
MASS OF THE WINE AT 18* C : LT = 169.2799 - ( 67.6695 + 0.0018 ) = 101.6086
APPARENT DENSITY OF THE WINE AT 18* C : *
3 . CALCULATION OF THE DENSITY OF A WINE AT 20* C :
PROCEED AS SPECIFIED ON PAGE 5 .
SECOND USUAL METHOD
DENSIMETRY BY THE HYDROSTATIC BALANCE
APPARATUS AND CALIBRATION OF THE FLOAT
THE HYDROSTATIC BALANCE , OF MAXIMUM CAPACITY NOT LESS THAN 100 G , MUST HAVE A SENSITIVITY OF 0.1 MG .
UNDER EACH PAN IS FIXED A PYREX ( 8 ) GLASS FLOAT OF VOLUME AT LEAST 20 ML . A VOLUME OF 50 OR 100 ML IS PREFERABLE . THESE TWO IDENTICAL FLOATS MUST BE SUSPENDED BY A THREAD OF DIAMETER NOT EXCEEDING 0.1 MM .
THE FLOAT SUSPENDED BENEATH THE RIGHT-HAND PAN MUST BE ABLE TO BE INTRODUCED INTO A CYLINDRICAL TEST-TUBE BEARING A MARK INDICATING THE LEVEL . THIS TEST-TUBE MUST HAVE AN INTERNAL DIAMETER AT LEAST 6 MM LARGER THAN THAT OF THE FLOAT . THE FLOAT MUST BE CAPABLE OF BEING CONTAINED COMPLETELY IN THE VOLUME OF THE TEST-TUBE SITUATED BELOW THE MARK ; THE SURFACE OF THE LIQUID TO BE MEASURED MUST BE TRAVERSED ONLY BY THE SUSPENSION THREAD . THE TEMPERATURE OF THE LIQUID PRESENT IN THE TEST-TUBE IS MEASURED BY A THERMOMETER GRADUATED IN DIVISIONS OF 0.2* C .
CALIBRATION OF THE APPARATUS
WITH THE TWO FLOATS IN AIR ONE FINDS THE BALANCED POSITION BY PLACING WEIGHTS MARKED P ON THE RIGHT-HAND PAN .
THE TEST-TUBE IS FILLED WITH PURE WATER UP TO THE MARK AND THE TEMPERATURE , T* C , IS MEASURED AFTER SHAKING AND ALLOWING TO STAND FOR TWO TO THREE MINUTES . THE BALANCED POSITION IS FOUND ONCE AGAIN BY MEANS OF MARKED WEIGHTS PLACED ON THE RIGHT-HAND PAN . LET THESE WEIGHTS BE P' .
THE VOLUME ( 9 ) OF THE FLOAT AT 20* C IS EQUAL TO V20 = ( P' - P ) ( F + 0.0012 ) ;
WHERE :
F IS THE FACTOR GIVEN IN TABLE I ,
P AND V20 ARE THE CHARACTERISTICS OF THE FLOAT , BECAUSE THEY DO NOT VARY WITH THE AIR PRESSURE , WHICH IS COMPENSATED FOR BY THE CALIBRATED FLOAT OF THE LEFT-HAND PAN .
PROCEDURE
THE RIGHT-HAND FLOAT IS IMMERSED IN THE TEST-TUBE FILLED WITH WINE ( OR MUST ) UP TO THE MARK . LET T* C BE THE TEMPERATURE OF THE WINE ( OR MUST ) AND P'' BE THE MARKED WEIGHTS WHICH RE-ESTABLISH THE BALANCED POSITION . THE APPARENT DENSITY , * , IS GIVEN BY THE FORMULA : ( SEE OJ )
THIS DENSITY IS CORRECTED TO 20* C BY USING ONE OF TABLES II TO IV , IF THE FLOAT IS OF PYREX GLASS , OR