BS 17409:2020 pdf download – Surfaces for sports areas – Code of practice for the sampling of performance infills used within synthetic turf surfaces
4 General
The method of sampling employed shall be designed and controlled to ensure that contamination of the increment, lot, sample, test portion or test sample cannot occur.
When laboratory samples are being taken for chemical analysis increments and samples shall be stored in containers that are known to not influence the results of the analysis.
NOTE Metal or glass containers are considered to satisfy this requirement.
All equipment shall be thoroughly cleaned before use.
5 Method 1 — sampling during production
5.1 Sampling plan
The main principle of sampling is to obtain a representative sample(s) from a lot of material from which a characteristic is to be determined. If the lot is to be represented by a sample, then every particle in the lot shall have an equal probability of being included in the sample.
When these principles cannot be applied in practice, the sampler shall define a judgemental sampling procedure that is designed to ensure the sampling matches as far as possible the outcomes of probability sampling and note any limitations of the procedure used in the sampling plan and sampling report.
Obtaining samples that are truly representative of the material produced is easier when the material is falling or moving (for example on a conveyor belt). Therefore, sampling from falling or moving material shall be undertaken wherever possible.
A sampling plan shall be prepared before samples are taken. This shall include a specific definition of the lot size and the size and number of increments to be taken.
5.2 Lot size
The minimum lot size shall be 10 t and the maximum lot size shall not exceed 120 t of product.
NOTE 1 A lot size of 120 t is based on the typical quantity of infill used on a 60 mm full size synthetic turf football field.
When determined by the producer the lot size may be defined as:
a) a fixed quantity produced between machine settings;
b) a fixed quantity in a production day/shift;
c) a fixed quantity;
d) a quantity produced in a fixed time frame.
NOTE 2 Option d) is most appropriate for continuous production with no beginning and no end.
5.3 Sampling point and apparatus
Based on health and safety assessments and producer equipment, a fixed sampling point for the collection of sample increments shall be chosen for each material fraction to be monitored. Sampling shall be carried out using a sample box or other suitable equipment.
The sampling box shall be passed through the stream of falling material so that it uniformly cuts the full flow of falling material. The box shall be large enough so that it does not become overloaded. Automatic systems fulfilling these criteria may also be used.
NOTE A procedure for preparing samples for chemical analysis is given in Annex A.
5.4 Size of sample increment
The sampling box shall have a capacity of not less than 0,5 l (0,000 5 m 3 ).
The sampling operator shall record the approximate capacity of the sampling device in cubic decimetres.
5.5 Number of increments
One increment shall be taken per 10 t of produced infill, with a minimum of four increments per lot.
Where daily or weekly production quantities are small, the taking of increments should be increased to ensure the lot comprises at least four increments.
6 Method 2 — sampling from big bags
6.1 Principle
The laboratory sample is created by mixing several increments removed with a sampling tool from at least three levels, with at least one located on each level, as specified in 6.3.
6.2 Apparatus
6.2.1 Sampling tool
This tool shall be designed to take samples of dry or slightly cohesive wet materials,. It shall be shaped in such a way to allow the operator to reach different heights by simply screwing the tool into the big bag. Its opening shall be wider than three times the size of the largest particle expected to be present in
the big bag.
6.2.2 Measuring flask
Container of known volume; greater than 1 l (0,001 m 3 ).
6.2.3 Container
Containers shall be used to recover the increments.