GB/T 4472-2011Detemination of density and relative density for chemical products (English PDF)

3.1 Density

It refers to the result of mass divided by volume. rho = m/V. It is expressed in kilograms per cubic meter (kg/m3) or in multiples thereof. mega-gram per cubic meters (Mg/m3), kilograms per cubic decimeters (kg/dm3), or gram per cubic centimeters (g/cm3).

3.2 Relative density

It refers to, under the given conditions, the ratio of the density of a substance to the density of another reference substance.

3.2.2 Relative density of liquid

It refers to, under the ambient temperature (20 °C), the ratio of the density of a substance to the density of water at 4 °C. It is expressed by the relative density d (water = 1).

3.2.3 Relative density of gas

It refers to, under the given conditions, the ratio of the vapor density of a gas or the vapor density of a substance to the density of the reference substance (air).

4.1 General requirements

4.1.1 All instruments shall be clean AND dried and calibrated before use.

4.1.2 When heating the sample, it shall avoid the error due to the loss of volatile components.

4.2 Determination of solid density

4.2.1 Requirements for test specimens

4.2.2 Method 1.density bottle method

4.2.2.1 Method summary

PLACE the sample into the density bottle of known volume; ADD the determination medium; AND the sample volume can be calculated by subtracting the volume of the medium under determination from the volume of the density bottle. Then the sample density is the ratio of the mass of the sample to its volume.

4.2.2.2 Instruments

4.2.2.3 Test conditions

4.2.2.3.1 The determination medium shall be pure AND shall not dissolve, swell and react with the test specimen; BUT the surface of the test specimen shall be moistened by the medium.

4.2.2.3.2 The determination medium is generally water, AND it may also select other media (such as xylene, kerosene, etc.).

4.2.2.4 Operating procedure

4.3.1.2 Instruments

4.3.1.2.1 Analytical balance. the division value is 0.0001 g.

4.3.1.2.2 Density bottles. (25 ~ 50) cm³ (SEE Figure 1 and 4).

4.3.1.2.3 Constant temperature water bath. temperature controlled at (20 ±

0.1) °C.

4.3.1.2.4 Thermometer. the division value is 0.1 °C

4.3.1.3 Operating procedure

4.3.1.3.1 WASH and DRY the density bottle; WEIGH it with plug.

4.3.2 Method 2.Wechsler balance method

4.3.2.1 Principles

In the water and the determination test specimen, respectively MEASURE the buoyancy of the "floating hammer"; through the reading of the rider, CALCULATE the density of the test specimen.

4.3.2.2 Instruments

4.3.2.2.1 Wechsler balance (SEE Figure 5).

4.3.2.2.2 Constant temperature water bath. temperature controlled at (20 ±

0.1) °C.

4.3.2.2.3 Thermometer. the division value is 0.1 °C.

4.3.2.3 Operating procedures

4.3.2.3.1 INSTALL the Wechsler balance; HANG the floating hammer onto the small hook through the fine platinum wire; ROTATE the regulation screw to make the two pointers align with each other.

4.3.3 Method 3.Density meter method

4.3.3.1 Method summary

From the depth of the density meter as immersed in the determination liquid when it reaches to the equilibrium state, READ out the density of this liquid.

4.3.3.2 Instruments

4.3.3.2.1 Density meter. the division value is 0.001 g/cm³ (SEE Figure 6).

4.3.3.2.2 Constant temperature water bath. temperature controlled at (20 ±

0.1) °C.

4.3.3.2.3 Glass tube. 250 mL ~ 500 mL

4.3.3.2.4 Thermometer (0 ~ 50) °C, the division value of 0.1 °C.

4.3.3.3 Operating procedures

4.3.3.4 Test results

4.3.3.4.1 The density rho t as determined at room temperature t °C is expressed in gram per cubic centimeter (g/cm3) AND calculated in accordance with the equation (8).

4.4 Determination of gas density

4.4.1 Method 1.Density bottle method

4.4.2.2 Instruments

4.4.2.2.1 Gas diffusers (SEE Figure 10).

4.4.2.2.2 Thermometer. (0 ~ 50) °C, AND the division value is 0.1 °C.

4.4.2.2.3 Stopwatch. the division value is 0.1 s.

4.4.2.3 Operating procedures

4.4.3 Result calculation

4.4.3.1 Under normal conditions, the relative density d of gas is calculated in accordance with the equation (12).

4.4.3.3 The density rho of the determination gas is expressed in grams per cubic decimeter (g/dm3) AND calculated in accordance with the equation (15).