BS ISO 8502-15 pdf free download

BS ISO 8502-15-2020 pdf free download.Preparation of steel substrates before application of paints and related products – Tests for the assessment of surface cleanliness Part 15: Extraction of soluble contaminants for analysis by acid extraction.
Mildly acidic solutions, with pH 3,6 ± 0,3 shall be used to dissolve the contaminants. The method of analyses after extraction and the solvent shall be selected properly. The mildly acidic solutions shall not contain the ion(s) of interest (e.g. chloride, sulfate, nitrate) or an acid that interferes with the titration analysis, such as phosphoric acid.
The solvent used shall be specified in the report.
NOTE Examples of suitable weak acid from the carboxylic or sulphonic acid chemistry are sulphamic acid
and hydroxy-acetic acid.
5.4 Contact thermometer
Accurate to 0,5 °C and graduated at 0,5 °C intervals.
6 Procedure
6.1 Selection of test surface
Choose test areas which are representative of the entire surface. Otherwise, it is important to select test areas where metal loss or pitting is observed, and on or around metal welds, as these are the areas where salts will be most prevalently concentrated.
6.2 Extraction by patch or sleeve by injection
6.2.1 Take an adhesive patch or sleeve (51) of a suitable size (see Table 1). Remove the protective paper; for the patch remove the punched-out material (see Figure 1).
6.2.2 Press the adhesive side of the patch or sleeve against the test surface (see Figures 2 and 7) in such a way that the minimum amount of air is trapped in the compartment in the patch.
6.2.3 Fill the syringe (&Z) with solvent (&3) (see Eigure3).
NOTE The volume of solvent needed to fill the patch compartment is proportional to the compartment area and normally amounts to 2,6 x 10-3 mI/mm2 ± 0.6 x 10-3 mI/mm2. The volume of solvent needed to fill the sleeve compartment is proportional to the compartment area and normally amounts to 10,0 x 10-3 mI/mm2 ±0,6 x 10 mI/mm2 (10 ml for S-bOO sleeve).
6.2.4 Insert the syringe needle at an angle of about 30° to the test surface near the outer edge of the patch or sleeve, so that it passes through the adhesive foam body of the patch or sleeve into the compartment formed between the elastomer film and the test surface (see Figure 4).
If the patch or sleeve is in a position which makes access to the patch compartment difficult, bend the syringe needle as required.
6.2.5 Inject the solvent, ensuring that it wets the whole of the test surface (see Figure 4).
If necessary, to avoid air remaining trapped in the patch compartment, carry out the injection in two steps as follows: inject half of the solvent. When required, evacuate the air through the needle by reverse operation of the syringe. Remove the needle from the patch or sleeve. Holding the syringe with the needle pointing upwards, expel the air. Reinsert the needle into the compartment and inject the remainder of the solvent.
6.2.6 After a suitable period, to be agreed between the interested parties, suck the solvent back into the syringe (see Figure 5). During this period, agitate the solution in the patch without removing the syringe needle from the patch or sleeve. The solution can be agitated by reinjecting the solvent into the compartment. Then suck the solvent back into the syringe cylinder at least four times or massaging the patch or sleeve to create solvent movement over the test surface.
6.2.7 Transfer the solvent to a suitable vessel for analysis (see Figure 6) as required for the analysis method.
6.2.8 During steps ff23 to 6.2.7. it is essential that no solvent be lost from the cell or syringe, due for instance to inferior-quality materials or improper handling of the materials. If any solvent is lost, the solution obtained shall be rejected.
6.2.9 On completion of step 62J, clean and rinse the syringe so that it can be reused. A bent needle is best left as it is until it becomes necessary to straighten it or bend it further.
6.3 ExtractIon by sleeve by pre-filling
6.3.1 Take an adhesive sleeve (&1) of a suitable size (see Table 1). Remove the protective paper and straighten the sleeve.
6.3.2 Prefill the sleeve with the required volume of solvent (5,3) and adhere the patch to the surface without loss of solvent (see Figure 7).
NOTE The volume of solvent needed to fill the sleeve compartment is proportional to the compartment area and normally amounts to 10,0 10-3 mI/mm2 ± 0,6 x 103 mi/mm2.
6.3.3 Position the sleeve such that all solvent in the sleeve is in contact with the surface.
6.3.4 During a suitable period of time, to be agreed between interested parties, or recommended by the manufacturer of the test equipment, agitate the sleeve several times by massaging the solvent on the surface. After the time period, let the sleeve hang down in order for the solvent to flow into the compartment of the sleeve.
6.3.5 Carefully remove the sleeve from the surface. Retain the solvent for further analysis.BS ISO 8502-15 pdf download.