ISO 19840:2004 Paints and varnishes - Anticorrosion of steel structures by painting systems - Measurement and acceptance criteria of the thickness of a dry film on rough surfaces (Second edition)
This International Standard specifies a procedure for the verification of dry film thickness against nominal dry film thickness on rough surfaces, including the adjustment of the instruments used, the definition of inspection areas, sampling plans, measurement methods and acceptance/rejection criteria.
For the purposes of this standard, any specified thickness is taken to be nominal as defined in ISO 12944-5 and the dry film thickness is the typical thickness above the peaks of the surface profile.
The procedure described in this International Standard is based on the use of instruments of the permanent magnet and inductive magnet type. Instruments are adjusted to zero and a known thickness on a smooth surface.
Measurements taken on a coating on a roughened steel substrate will therefore be higher than the actual value above the peaks of the profile. The thickness of the dry film above the peaks of the profile is defined as the instrument reading minus an appropriate correction value.
The dry film thickness is obtained by using the appropriate correction value applied to readings based on adjustment on a smooth, flat, steel surface.
Where individual readings, based on adjustment on a smooth, flat steel surface without the use of correction values, are specified or agreed, it is important to recognise that this method does not conform with this International Standard.
This standard is applicable if the nominal dry film thickness is 40 μm or greater.
NOTE If the nominal thickness is less than the surface roughness of the substrate the uncertainty of the measurement will increase.
ISO 19840:2004 Referenced Document
ISO 12944-1 Paints and varnishes - Corrosion protection of steel structures by protective paint systems - Part 1: General introduction*, 2017-11-01 Update
ISO 12944-2 Paints and varnishes - Corrosion protection of steel structures by protective paint systems - Part 2: Classification of environments*, 2017-11-01 Update
ISO 12944-3 Paints and varnishes - Corrosion protection of steel structures by protective paint systems - Part 3: Design considerations*, 2017-11-01 Update
ISO 12944-4 Paints and varnishes - Corrosion protection of steel structures by protective paint systems - Part 4: Types of surface and surface preparation*, 2017-11-01 Update
ISO 12944-5 Paints and varnishes — Corrosion protection of steel structures by protective paint systems — Part 5: Protective paint systems*, 2019-09-27 Update
ISO 12944-6 Paints and varnishes - Corrosion protection of steel structures by protective paint systems - Part 6: Laboratory performance test methods*, 2018-01-01 Update
ISO 12944-7 Paints and varnishes - Corrosion protection of steel structures by protective paint systems - Part 7: Execution and supervision of paint work*, 2017-11-01 Update
ISO 12944-8 Paints and varnishes - Corrosion protection of steel structures by protective paint systems - Part 8: Development of specifications for new work and maintenance*, 2017-11-01 Update
ISO 2808 Paints and varnishes — Determination of film thickness*, 2019-07-26 Update
ISO 19840:2004 history
2012ISO 19840:2012 Paints and varnishes - Corrosion protection of steel structures by protective paint systems - Measurement of, and acceptance criteria for, the thickness of dry films on rough surfaces
2004ISO 19840:2004 Paints and varnishes - Anticorrosion of steel structures by painting systems - Measurement and acceptance criteria of the thickness of a dry film on rough surfaces (Second edition)