ASTM D1480 Test Method for Density and Relative Density (Specific Gravity) of Viscous Materials by Bingham Pycnometer
6. Apparatus
6.1 Pycnometer, Bingham-type of 10-mL capacity (as shown in Fig. 1), constructed of heat-resistant glass.
NOTE 2 - Pycnometers having capacities of 2 to 25 mL are available but have not been cooperatively evaluated.
6.2 Constant-Temperature Bath, provided with suitable pycnometer holders and means for maintaining temperatures constant to +/-0.01°C in the desired range. Water-glycerin mixtures can be used for temperatures up to 100°C.
6.3 Bath Thermometer, graduated in 0.1°C subdivisions and standardized for the range of use to the nearest 0.01°C (ASTM Saybolt Viscosity Thermometers 17C to 22C, conforming to the requirements in Specification E 1, are recommended). For most hydrocarbons the density coefficient is about 0.0008 units/°C, and therefore an error of +/-0.013°C would cause an error of +/-0.00001 in density.
6.4 Thermal Shields, as shown in Fig. 2 , to hold the pycnometer and syringe during the filling procedure, constructed of two aluminum shells with suitably spaced viewing ports, the upper bored to hold a 30-mL hypodermic syringe and the lower bored to hold a 25-mL Bingham pycnometer. A winding of No. 26 Chromel "A" wire, insulated from the shields with mica, covered with insulating tape, and having resistances connected in series of 25 Ω on the upper shield and 35 Ω on the lower produces controlled heat to the shields by means of a variable transformer. A stand is necessary to support the shields in such a manner that the center of the wells may be aligned, and the upper shield raised 180 to 200 mm and swung through 45°.
6.5 Hypodermic Syringes, 2 to 30-mL capacity, of chemically resistant glass, equipped with a 170-mm, 16-gage (0.065 in.) filling needle made from stainless-steel tubing, as shown in Fig. 3.
6.6 Draw-off Needle, made of stainless-steel tubing, as shown in Fig. 3.
6.7 Solvent Cleaning Assembly, as shown in Fig. 4.
6.8 Chromic Acid Cleaning Apparatus, similar to that shown in Fig. 5.
6.9 Balance, capable of reproducing weighings within 0.1 mg when carrying a load of 30 g. The balance shall be located in a room shielded from drafts and fumes and in which the temperature changes between related weighings (empty and filled pycnometer) do not cause a significant change in the ratio of the balance arms. The same balance shall be used for all related weighings.
6.10 Weights, whose relative values are known to the nearest 0.05 mg or better. Use the same set of weights for the calibration of the pycnometer and the determination of densities.
7. Reagents and Materials
7.1 Acetone - (Warning - See Note 3).
NOTE 3 - Warning: Extremely flammable. Use adequate ventilation.
7.2 Isopentane - (Warning - See Note 4).
NOTE 4 - Warning: Extremely flammable. Avoid build up of vapors and remove all sources of ignition, especially non-explosion proof electrical apparatus.
7.3 Chromic Acid (Potassium Dichromate/Conc. Sulfuric Acid) - (Warning - See Note 5).
NOTE 5 - Warning: Causes severe burns. A recognized carcinogen. Do not get in eyes, on skin or clothing.
