Standard
STD 420-0003
Volvo Group
Version
1
Page
7
Note: If the film of fluid contracts, this means that the tensile adhesion with the glass is less than the surface
tension of the fluid. If it spreads, the tensile adhesion with the glass is greater than the surface tension of the fluid.
6.1.2.2 Manual cleaning
6.1.2.2.1 General
The seals, metal rings and beakers are washed after each test in accordance with the process described below
(6.1.2.2.2, 6.1.2.2.3 and 6.1.2.2.4) and kept in a dust-free environment between the tests.
The glass plates shall be washed before the test (6.1.2.2.5) and stored for 1 h maximum without coming into
contact with each other, in a dust-free environment.
Note: Avoid using compressed air to dry the material, as this may be a source of heavy pollution.
6.1.2.2.2 Cleaning seals
The seals are washed with the laboratory washing product, rinsed abundantly in water, then in distilled water and
dried at ambient temperature. Before each test, the seals must be placed for 1 h minimum in an oven set to 120 °C
to avoid the release problem.
6.1.2.2.3 Cleaning metal ring
Metal rings are not to be touched with bare hands. The rings are washed with the laboratory washing product,
rinsed abundantly in water, then in distilled water and dried using paper.
6.1.2.2.4 Cleaning of beakers
The beakers must be touched on the outer surfaces only.
The beakers are washed with the laboratory washing product and soft paper, rinsed abundantly in water, then in
distilled water. Allow them to drain for a few moments, then wipe with paper.
If the beakers have contained greasy products or if the specimens have become damaged during the test leaving a
deposit on the bottom of the beakers, the beakers shall be washed in acetone before performing the above-
mentioned washing procedure.
6.1.2.2.5 Cleaning of glass plates
Wash each plate with a different cotton wad impregnated with acetone so as to remove deposits.
Wash with the laboratory washing product, paper (4.19) and hot water rinse abundantly in water, then in distilled
water.
Dry using paper (4.19), and then place the plates in acetone for 30 minutes minimum.
The acetone baths shall be changed after every 5 operations.
When removed, allow the plates to dry in ambient air. If traces due to evaporation of the acetone appear, rinse the
plate in acetone and dry it with paper (4.19).
Note: The washing stage is highly important, since the appearance of a deposit is greatly dependent on the surface
tension of the glass.
After the glass plates have been cleaned and dried, check their cleanliness at a point at which no condensation can
occur during the test by applying a thin film of test fluid (3.4) to the glass surface. The edges of the film shall not
contract within 2 s. Should the edges contract within this time, repeat the cleaning procedure. Should the edges
even after repeated cleaning still contract within 2 s, do not use these plates again for measurements. Make a
visual check that the plates are free of scratches and other defects; if they are not, discard tem.
Note: If the film of fluid contracts, this means that the tensile adhesion with the glass is less than the surface
tension of the fluid. If it spreads, the tensile adhesion with the glass is greater than the surface tension of the fluid.
