ISO 16122-4:2015, when used together with ISO 16122-1, specifies the requirements and test methods for the inspection of fixed and semi-mobile sprayers, when in use.
The requirements relate mainly to the condition of the sprayer with respect to its potential risk for the environment and its performance to achieve good application.
It does not apply to application equipment for spatial treatment (e.g. foggers).
Note that requirements for the protection of inspectors during an inspection are given in ISO 16122-1.