Density of water in gl4/14/2024 ![]() ![]() Where p" represents the mass in grams that makes up the equilibrium at t☌, Weigh the pycnometer filled with the test sample following the instructions outlined in A.4.1.1. Tare weight: P – m where m (g) = mass of the air contained in the pycnometer the mass of the water-filled pycnometer at t ☌: P 1 following the instructions outlined in A.4.1.1,.the mass of the clean, dry pycnometer: P,.= factor for temperature, t☌, taken from Table I Tare weight = p + m where m (g) = mass of the air contained in the pycnometer Weigh the water-filled pycnometer, with the weight in grams, p', making up the equilibrium. Read the temperature, t ☌, carefully and if necessary correct for any inaccuracies in the temperature scale. Shake by inverting the container until the thermometer's temperature reading is constant, accurately adjust the level to the upper rim of the side tube, wipe the side tube clean and fit the reservoir stopper. Balance them by placing weights of known mass on the pycnometer side: p grams.įill the pycnometer carefully with water (A.2.1) at room temperature and fit the thermometer.Ĭarefully wipe the pycnometer dry and place it in the thermally insulated jacket. Place the tare bottle on the left-hand pan and the clean, dry pycnometer with its 'reservoir stopper' on the right-hand pan. The calibration of the pycnometer comprises the determination of the following characteristics: ![]() Single-plate balance accurate to the nearest 0.1 mg.Ī.3.5. Twin-pan balance accurate to the nearest 0.1 mg Thermally insulated jacket that fits the body of the pycnometer exactly.Ī.3.4. Tare bottle of the same external volume (to within 1 mL) as the pycnometer and with a mass equal to the mass of the pycnometer filled with a liquid of a density of 1.01 g/mL (sodium chloride solution at 2% m/v)Ī.3.3. The two joints of the apparatus should be prepared with great care.Ī.3.2. This stopper serves as an expansion chamber. This side tube may be capped by a 'reservoir stopper' composed of a ground-glass conical tube, terminated by a tapered joint. This pycnometer includes a side tube of 25 mm in length and an inside diameter of at most 1 mm, terminated by a ground-glass conical joint. 1).Īny pycnometer of equivalent characteristics may be used. This thermometer should be calibrated (Fig. Pyrex-glass pycnometer of around 100 mL capacity with a removable thermometer, with ground-glass joint and 10 th-of-a-degree graduations, from 10 ☌ to 30 ☌. To prepare 1 litre, weigh out 20 g of sodium chloride and dissolve to volume in water.Ĭurrent laboratory apparatus, including the following:Ī.3.1. Type II water for analytical use (ISO 3696 standard), or of equivalent purity The volumes of the flask and the capillary being known, the density is determined by weighing using precision balances before and after filling of the pycnometer.Ī.2.1. When the flask is closed, the overflow rises in the capillary. This comprises a flask of known capacity, onto which a hollow ground-glass stopper is fitted equipped with a capillary tube. The density of the wine or must is measured for a specific temperature using a glass pycnometer. Method A: Density at 20 ☌ and specific gravity at 20 ☌ measured by pycnometry (Type method) If the wine or must contains notable quantities of carbon dioxide, remove the grand majority by, for example, mixing 250 mL of sample in a 1000-mL vial, or by filtering under reduced pressure on 2 g of cotton placed in an extension tube, or by any other suitable method. Note: For very precise determinations, the density should be corrected to account for sulphur-dioxide action. Method C: Densimetry using a hydrostatic balance Method B: Electronic densimetry using a frequency oscillator The principle of each method is detailed in the following parts: Note: It is possible to obtain the specific gravity from the density ρ 20 at 20 ☌: For the analysis of wine or must, it is typically expressed as the ratio of the density of the wine or must at 20 ☌ to the density of water at 20 ☌. The specific gravity is the ratio of the density of a substance to the density of a reference material. It is expressed in g/cm 3 and its symbol is ρ 20☌. Densimetry using a hydrostatic balance: Type I Method,ĭensity is the quotient of the mass of a certain volume of wine or must at 20 ☌ by this volume.Electronic densimetry using a frequency oscillator: Type I Method,.This resolution is applicable for determining the density and specific gravity at 20 ☌ of wines and musts, using any of the following: OIV-MA-AS2-01 Density and specific gravity at 20☌ ![]()
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