Read the test conditions.
Understand airflow, water resistance and system-level verification.
Airflow and pressure differential
Airflow is measured under a pressure difference. A value without its differential, unit and specimen definition is incomplete for engineering comparison. Ask whether the result is for the membrane area or the finished assembly.
Water-entry pressure and IP tests
Water-entry pressure and an ingress-protection test describe different conditions. Do not substitute one for the other. Review immersion depth, duration, test orientation and any preconditioning stated for the configuration.
Acoustic membranes
Sound transmission and water resistance must be evaluated together. Compare acoustic loss at the stated frequency and consider the complete acoustic path, mounting cavity and attachment method.
Validate the enclosure
The vent, gasket, mating surface and surrounding enclosure form one system. A component rating is not an automatic rating for the final device. Agree a test plan that matches the use environment and acceptance criteria.