109 2012.10.02 Density
109 2012.10.02 Density
109 2012.10.02 Density
Adopted:
2 October 2012
INTRODUCTION
1. This Test Guideline is a revision of the Test Guideline 109 originally adopted in 1981 and first
revised in 1995. This revision adds CIPAC MT 186 (1) published in 2003, which supersedes MT 159 cited
by OPPTS 830.7300 (2) as an option for density determination: the major revision in 2012 is inclusion of
pour and tap (solid).
INITIAL CONSIDERATIONS
2. Most methods for determining the density of liquids and solids are the object of national and
international standardizing bodies and are frequently specified by governmental agencies. This Guideline
lists these methods, giving only a very succinct description of them, and the reader is referred to the
standards which are listed in the appendix. Some other methods mentioned in the Guideline are taken from
the scientific literature, and again only succinct information is given on the methods.
SIGNIFICANCE
4. This Test Guideline provides procedures to obtain density of chemicals (substances and
mixtures). The data may be used to assess the manner and extent that chemicals and components of
mixtures will be transported in the environment and locations where they may be deposited.
5. The density, ρ is the quotient of mass, m, and volume, V, and is expressed in SI units as kg/m3 at
a specified temperature. The relative density (D20/4, density at 20 degrees Centigrade relative to water at 4
degrees Centigrade) may be used to compare different chemicals.
REFERENCE SUBSTANCES
6. Reference substances, or liquids of known density, need to be employed when determining the
density of a chemical by oscillating densitometry.
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109 OECD/OCDE
7. Hydrometers are weighted glass floats which sink into the liquid to a depth dependent on the
density. The density is read at the level of the liquid on a calibrated stem extending above the liquid. The
dynamic viscosity of the liquid to be investigated should not exceed 5 Pa.s.
8. The density of a solid is derived from the difference in weight between a sample in air and in a
liquid of known density (e.g. water). The density thus measured is only representative of the particular
sample employed (bulk density).
9. For the determination of density of liquids, a solid body of known volume is weighed first in air
and then when immersed in the liquid. The dynamic viscosity of liquids to be investigated should not
exceed 5 Pa.s.
10. A vessel containing a sample of the liquid test substance is placed on a balance and weighed.
Then, a body of known volume (generally a sphere of approximately 10 cm3 made of metal), which is
clamped to a stand independent from the balance, is immersed in the liquid. The action exerted by the
immersed body on the balance cannot be distinguished from that of a freely floating body with a volume
identical with that of the immersed body and having the density of the surrounding liquid. The density of
the liquid is obtained by dividing the gain in weight due to the immersion of the body by the known
volume of the body. The method is applicable to liquids with a dynamic viscosity below 20 Pa.s (3).
11. The density is calculated from the difference in weight between the full and empty pycnometer
and its volume. In the case of liquids, the dynamic viscosity should not be above 500 Pa.s.
12. The volume of a sample of the solid is measured in air or in an inert gas in a calibrated cylinder
of variable volume. After concluding the volume measurement, the sample is weighed.
13. A mechanical oscillator, constructed in the form of a U-tube, is vibrated at its resonance
frequency which depends on its mass. Introducing a sample changes the resonance frequency. The
apparatus should be calibrated with two liquids of known density. The liquids should preferably be chosen
such that their densities span the range into which the liquid under investigation falls. The method is
applicable to liquids with a dynamic viscosity below 5 Pa.s.
14. A known weight of a solid material is placed in a glass graduated (i.e. measuring) cylinder and its
volume measured to determine the ‘pour density.’ The cylinder is then raised and allowed to fall vertically
through a distance of 25 mm on a rubber pad 50 times (or this may be performed using a Dry Substance
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Jolting Volumeter as described in ISO 787/11). The volume is measured again to determine the ‘tap
density.’
TEST CONDITIONS
15. The test is done at constant temperature, preferably at 20°C. Duplicate measurements are
required.
16. For the technical details of apparatus and procedures, the standards listed in the appendix should
be consulted.
TEST REPORT
-method used;
-estimated accuracy;
-results obtained with the reference substances when used for calibration or comparison;
-density (the mean of at least two measurements which are in the range of the estimated
accuracy);
-the dynamic viscosity of liquids to confirm that the method chosen was appropriate for the
substance;
-all information and remarks relevant for the interpretation of the results, especially with regards
to impurities and physical state of the substance.
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LITERATURE
1. Collaborative International Pesticide Analytical Council, Ltd. (CIPAC) (2003), Handbook K, “MT
186 Bulk Density” CIPAC, ( 2003). www.cipac.org , Publications available from: Marston Book
Services Ltd.: (http://www.marston.co.uk)
2. United States Environmental Protection Agency (EPA) (2002), Product Properties Test Guidelines
OPPTS 830.7300 “Density / Relative Density / Bulk Density,” EPA 712-C-02-035.
3. Wagenbreth, H. (1979), Die Tauchkugel zur Bestimmung der Dichte von Flüssigkeiten,
Technisches Messen, vol. 11, 427-430.
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LIST OF STANDARDS
Hydrometer
ASTM D 1298 Density, specific gravity or API gravity of crude petroleum and liquid
petroleum products by hydrometer method
BS EN ISO 3675 Crude petroleum and liquid petroleum products. Laboratory determination
of density. Hydrometer method
ISO 649-2 Density hydrometers for general purposes - Test methods and use
Hydrostatic balance
NF T 20-049 Chemical products for industrial use - Determination of the density of solids
other than powders and cellular products
ASTM D 1481 Test Method for Density and Relative Density (Specific Gravity) of Viscous
Materials by Lipkin Bicapillary Pycnometer
DIN 51757 Testing of mineral oils and related materials - determination of density
BS EN ISO 2811-2 Paints and varnishes - determination of density, Part 2: immersed body
(plummet) method
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Pycnometer
BS EN ISO 3838 Methods of test for petroleum and its products - BS 2000-189/190: crude
petroleum and liquid or solid petroleum products - determination of density
or relative density - capillary-stoppered pyknometer and graduated
bicapillary pyknometer methods
BS EN ISO 2811-1 Paints and varnishes - determination of density, Part 1: pyknometer method
ISO 758 Liquid chemical products for industrial use - Determination of density at
20°C
ISO 901 Aluminum oxide primarily used for the production aluminum-
Determination of absolute density
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