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ÖNORM EN ISO 8502-2:2006-08

Заменен
Preparation of steel substrates before application of paints and related products - Tests for the assessment of surface cleanliness - Part 2: Laboratory determination of chloride on cleaned surfaces (ISO 8502-2:2005)
This part of ISO 8502 describes a method for the determination of chloride-containing salts that are readily
soluble in water and are present on a steel surface. The method is also applicable to previously coated
surfaces. It will normally be used in a laboratory using washings sampled from surfaces on site.
The method is applicable to the determination of salts that have been deposited on the steel surface before,
during or after the cleaning operations.
NOTE 1 Although the procedure for chloride determination is generally accurate, the overall precision of the method is
limited by uncertainties in the sampling procedure. In addition, traces of iron chloride at the bottom of pits are difficult to
extract into the sample.
The test method is not applicable to surfaces treated with chromate, nitrite or amine, which are commonly
used as inhibitors in the water when wet blast-cleaning. This is because a chromate concentration of 10 mg/l
or greater or a nitrite concentration of 20 mg/l or greater in the wash water interferes with the determination of
the chloride. Also the amine inhibitors can form a hydroxide boundary layer (not water soluble) over the
substrate and prevent the water from contacting the underlying salt for its removal.
An iron(III) ion concentration of 10 mg/l also interferes with the determination, but the iron(III) ions are
concentrated in the rust deposits, which are removed from the test solution by filtration.
NOTE 2 The performance of a paint system is affected by the amount of soluble chloride remaining on the surface. The
acceptable level of this contamination is related to the service conditions. For further information regarding levels of watersoluble
salt contamination see ISO/TR 15235 [1].
Dieser Teil von ISO 8502 beschreibt ein Verfahren zum Bestimmen von in Waser leicht löslichen chloridhaltigen Salzen, die sich auf einer Stahloberfläche befinden. Das Verfahren ist auch bei beschichteten Oberflächen anwendbar. Es wird üblicherweise in einem Labor an Waschflüssigkeiten durchgeführt, die auf Baustellen von Oberflächen gesammelt wurden. Das Verfahren ist zum Bestimmen von Salzen anwendbar, die durch den Reinigungsprozess eingeschleppt wurden oder die sich vor oder nach dem Reinigen abgelagert haben.
ICS
25.220.10 Surface. Including surface preparation for painting, cleaning, scouring, blasting, etc. / Подготовка поверхности. Включая подготовку поверхности под окраску, зачистку, шабрение, струйную очистку и т.д.