標準號：IS 2302-1989
發布日期：1990/6/1 12:00:00
實施日期：1999/12/31 12:00:00
適用范圍：1.1 This standard covers method of obtaining volumetric content of ethanol at 20°C (Table 1 ) and at 15°C and 15.56°C( Table 2) in an alcoholic solution ( ethanol-water ) using the centesimal hydrometers calibrated at 20°C.1.1.1 Table 1 gives alcohol-richness data, that is, ethanol content by volume at 20°C in the sample at t°C against the observed ( hydro-meter) degree at 0.1 degree interval at the observed temperature, t°C in the range 0° to 40°C. The volume conversion factor given in this table enables computation of real strength ( 20°/20° ). Also, the volume in litres per 100 kg ( in air ) of the sample at the observed degree is also incorporated in the same table. Table 2 gives the minor corrections for converting the real strength at the international reference temperature to that at 15.56°C or 15°C for use in the country until the adoption of inter-national reference temperature 20°C for excise purposes.NOTE — The volume in litres per 100 kg (in air) of the alcohol-water sample at the observed degree is computed from the OlML data, giving volume corresponding to 100 kg in vacuum, and applying the correction for buoyancy, β in air, given by β = mass ×air density × (reciprocal density of sample— reciprocal density of weights used). For mass = 100 kg, air density at 27°C = 0001177 g/cm3 and the density of cast iron weights as 7'3 g/cm3 we have β =0102 to 0.133 kg from alcohol strength 0 to 100 percent. The volume corresponding to 100 kg ( in air ) of alcohol-water samples thereby stands modified slightly by 0 1 litre to 100 .3-119.8 litres in the range 0 to 88 observed degree and by 0.2 litres to 120.3-126.9 litres in the range 89-100 observed degree as seen from the following table:Observed Density Volume in I Buoyancy Volume in I for AV in IDegree ( vac) for 100 kg Correction 100 kg ( in air ),( in vac) ( β ) for that is ( 100 +100 kg β) kg( in vnc )(V1) (kg) (V2) (V1-V2)0 0.998 20 100.180 0.102 100.282 0.1088 0.83564 119.660 0.1247 119.813 0 15-89 0.832 45 120.127 0.1253 120.278 015 + 100 0.789 24 126.704 0 133 126.873 0.17 103* 0.772 77 129.40 0.136 129.58 0.18*Imaginary alcohol content to take care of liquids with high alcohol content, the density of which at higher temperatures 20°-40°C, formally corresponds to alcohol content above 100 percent. The alcoholometers are adjusted at observed degree above 100 according to the densities given in IS 3608.