Sand/dust testing can cause a whole range of different failure modes, including:
- Penetration of enclosures or capsules
- Change of electrical properties (faulty contacting; change of contact resistance; change of creepage resistance).
- Seizure or restriction of movement of mechanical parts (bearings, axles, shafts, etc.)
- Wear of the surface (abrasion)
- Contamination of optical surfaces
- Contamination of lubricants
- Clogging of vents, reducers, pipes, filters, openings
Dust tests for the aviation sector are carried out together with an air flow to force the penetration of dust into products. For military equipment, the air speed is up to 9m/s (32km/h). The dust usually consists of talc, silica sand, feldspar and other minerals. Arizona dust, for example, is a combination of several components, China Clay is also sometimes used. The grain sizes are smaller than 150 µm.
Special tests can also be carried out with magnetic dusts or dusts containing fibers. This allows simulations of dusts in tunnels or in mining (coal dust) to be simulated.
Sands with grain sizes from 150µm to 850µm are preferred.