Approved is better!

SKL (Foundation for Quality Control of Agricultural Equipment) in Wageningen (the Netherlands) is the Dutch organisation for testing agricultural machines in use.

Periodical inspection of Air-assisted sprayers for bush and tree crops

The inspection of air-assisted sprayers in the Netherlands has started on voluntary base. But since 2002 the inspections are obligatry.
SKL organises and supervises the inspections. The inspections themselves are done by certified testing stations spread over the whole country. This testing stations have the right testing equipment to perform uniform inspections. The inspections are done by certified test-operators.
The tests are done on base of a uniform testing standard based on EN-13790(2):2003. In the nearby future this will be change to EN-ISO 16122-3.