ASTM D6822 for Density, Relative Density and API Gravity of Petroleum Products
ASTM D6822 Standard Test Method for Density, Relative Density, and API Gravity of Crude Petroleum and Liquid Petroleum Products by Thermohydrometer Method
6. Apparatus
6.1 Glass Thermohydrometers, as specified in Specification E 100 (shown in Fig. 1), and graduated in:
6.1.1 Kilograms/cubic metre (kg/m3) and degrees Celsius for density hydrometers, as shown in Table 1.
6.1.2 Degrees API (°API) and degrees Fahrenheit for hydrometers measuring in API Gravity, as shown in Table 2.
6.2 Hydrometer Cylinders, clear glass, plastic, or metal. For convenience of pouring, the cylinder may have a pouring lip. The inside diameter shall be at least 25 mm (1 in.) greater than the outside diameter of the thermohydrometer used. The height of the cylinder shall be such that the bottom of the thermohydrometer clears the bottom of the cylinder by at least 25 mm (1 in.) when suspended in the sample test portion.
6.2.1 For field testing, a sample thief of suitable dimensions may be more convenient than a hydrometer cylinder. The liquid level shall be level with the top of the thief.
6.3 Temperature Bath, to control temperature close to the bulk hydrocarbon temperature or to control temperature close to the reference temperature of 15°C or 60°F.
