Knowledge Base
Standards
ISO 2811 is an international ISO standard for reliable density testing of paints, varnishes and related products using a metal or Gay-Lussac pycnometer.
Pycnometers are used for measuring and comparing densities – or specific gravities – of liquids and solids. Pycnometer bottles are typically made of glass and have a ground glass stopper with a capillary tube for air bubbles to escape. They’re also made in metal and you can use either type when you’re performing ISO 2811 testing.
The ISO 2811 method is limited to materials of low or medium viscosity at the temperature of testing. However, if you need to test highly viscous materials then the purpose designed Hubbard pycnometer (see ISO 3507) can be used.
To undertake an ISO 2811 pycnometer test you’ll need to first fill a pycnometer with a sample of the product you’re testing. The density is calculated from the mass of the product in the pycnometer and the known volume of the pycnometer.
The effect of temperature on density is highly significant with respect to filling properties. So for international reference purposes, it’s essential to standardize one test temperature.
The ISO 2811 standard consists of the following parts:
Metal pycnometer
If you opt for a metal pycnometer then you should work with one that has a volume of either 50 cm3 or 100 cm3, a circular cross-section and a cylindrical form. It should be made of a smoothly finished corrosion-resistant material with a snugly fitting lid that has a hole in its center. The inside of the lid itself should be of a concave design.
Glass pycnometer
If you choose to work with a glass pycnometer then you’ll need a Gay-Lussac type with a volume in the range of 10 cm3 to 100 cm3. The Gay-Lussac Pycnometer features a glass body with a ground capillary stopper.
Analytical balance
Your ISO 2811 analytical balance should be accurate to 1 mg when using pycnometers for less than 50 ml, or accurate to 10 mg when using pycnometers of 50 ml to 100 ml in volume.
Thermometer
The thermometer you’ll need for ISO 2811 testing should have an accuracy of 0,2°C.
Temperature-controlled chamber
You’ll need a chamber that’s capable of accommodating the balance, pycnometer and test sample and maintaining them at the specified or agreed temperature. Or a water bath that can offer the same capability.
Additional ISO 2811 equipment
In addition to the right pycnometer, to carry out an ISO 2811 test you’ll need a selection of typical laboratory apparatus and glassware.
Within the ISO 2811 documents you get the following included:
So, how can Industrial Physics improve your ISO 2811 testing?
TQC Sheen pycnometers (specific gravity cups)
Our range of pycnometers from our paint testing specialist brand TQC Sheen are just what you need to determine the specific gravity or density of coatings, pastes or similar liquids. They’re available in anodized aluminum and stainless steel in 100 ml and 50 ml versions and all models are supplied with a calibration certificate.
TQC Sheen Pressure Density Cup
The TQC Sheen Pressure Density Cup was developed to provide highly accurate specific gravity measurements of a liquid’s density with a high level of repeatability.
Your global test and measurement partner for ISO 2811
Specific gravity cups, also known as density cups or pycnometers, are ideal for very accurate determination of the density of a liquid.
The TQC Sheen Pressure Density Cup was developed to provide highly accurate specific gravity measurements of a liquid’s density with a high level of repeatability.
Invest in a powerful ZR800 Series Oxygen Analyzer and you’ll measure the oxygen in most industrial gas streams from 0.1ppm up to 100% volumes.
© 2026 Industrial Physics. All rights reserved. Privacy Policy Manage consent