Sampling (clause 7.3)

From your explanation, if you are testing all the materials used for an installation, then sampling requirements would not apply to your activities. Sampling covers, simply, the taking of a unit or portion of a material, substance or product from the source so that a sample can be tested or calibrated. The intent is that the sampling plan and methodology results in a suitably representative sample for subsequent testing so as to represent the measurement result of the source. As you are doing the testing, look at the risk based on what you are reporting. If the report claims the consignment of aluminium curtain walls, doors and windows used in your installation is fit for purpose, or conforms to a specification; and your laboratory only tested a portion of the consignment, then you do need to comply with Clause 7.3, sampling requirement. The standard you use may state the sampling rate (number of units tested per units in the consignment), in which case you can reference the Standard and provide recorded evidence that the requirement were complied with.

If applicable, have a look at the ISO 17025 document template previews: Sampling Procedure available at https://advisera.com/17025academy/documentation/sampling-procedure/ as well as the 2 related appendices Sampling Plan at https://advisera.com/17025academy/documentation/sampling-plan/ and Sampling Report at https://advisera.com/17025academy/documentation/sampling-report/