Picnometer
Coatings & Industry > Physical properties > Density
Standards
BS 3900:A 12
SIS 18 41 11
SNV 37 100 VDA
621-103
DIN 53 217 ISO 2811
Density - PYCNOMETER Model 290
Establishment of the specific gravity of raw materials and of finished products when they are received is for many purposes standard practice.
Even at the final quality relevant pre-delivery-inspection the compliance of preselected data gives an important lead to the correct requested compounding of the present recipe.
Purpose and Application
Pycnometers are used to establish the density of coating materials and other fluids and paste products.
Test Principle
The density r of a substance is the ratio of its mass m to its volume V:
Unless otherwise specified, the density of the coating material is given at 20 °C.
The density at 20 °C may be specified as r20.
The density is measured by means of Pycnometers.
The Pycnometer container is filled with fluid. The difference in weight between the empty and full Pycnometer and it internal volume enables the density to be calculated.
Design and Function
The Pycnometers consist of a container and a lid with an overflow hole. There are two versions of Pycnometers available:
- Instruments made of anodized aluminium and
- Instruments made of stainless steel
each with a volume of
- 50 ccm or
- 100 ccm.
The standard ERICHSEN Pycnometers are made to a tolerance of 0.2 %. Upon request and at an extra price, all instruments can be made to a tolerance of 0.1 % and supplied with a certificate of the Official Bureau of Weights and Measures.
The 100 ccm Pycnometer is for general use, whereas the 50 ccm version is used primarily for paste materials, as it is easier to handle for this application.
Test Procedure
After being brought to 20 °C the Pycnometer is weighed and then filled with the specimen material, also at a temperature of 20 °C, up to a level just below the top edge, in such a way that trapping of air is avoided.
The lid is then placed into position with a light turning movement and surplus material escaping through the overflow hole is wiped off.
The instrument is then weighed again.
To open the Pycnometer a special opening aid can be supplied as accessory.
For exact calculations please refer to the formula described in DIN 53 217 - Part 2.
Special Note
In order not to impair the volumetric accuracy, hard or sharp objects should not be used for cleaning.
When establishing the density of acid or alkali substances, we recommend to use Pycnometers made of stainless steel only, as instruments made of anodized aluminium are not resistant against these substances.
Reference Class:
All Models 290 are supplied with a Manufacturer’s Certificate M in accordance with DIN 55 350-18 that includes among others the following information:
Volume (in cm3) of Pycnometer, product indification, test equipment used with calibration status, date, name of inspector.
The volumes of the Pycnometers are determined by using of distilled water as test medium (tolerance 0.2%). By an extra charge, the Pycnometers are also available with a tolerance of 0.05 %.
The Models 290 can also be supplied with a conformity assessment (instead of official calibration certificate, according to the new calibration law dated 01.01.2015)
Ordering Information
Ord.-No. Product Name
101-0018.02.31 Pycnometer, Model 290/I Anodized aluminium, volume 100 ml
101-0018.04.31 as Order No. 101-0018.02.31, but with conformity assessment and test certificate
101-0018.01.31 Pycnometer, Model 290/II Anodized aluminium, volume 50 ml
101-0018.03.31 as Order No. 0018.01.31, but with conformity assessment and test certificate
101-0163.01.31 Pycnometer, Model 290/V Stainless steel, volume 100 ml
101-0163.03.31 as Order No. 0163.01.31, but with conformity assessment and test certificate
101-0162.01.31 Pycnometer, Model 290/IV Stainless steel, volume 50 ml
101-0162.03.31 as Order No. 0162.01.31, but with conformity assessment and test certificate
Accessories
Ord.-No. Product Name
101-0476.01.32 Opening aid
