Purpose of Tests

a. Small-particle dust (≤ 149 μm). These tests are performed to help evaluate the ability of materiel to resist the effects of dust.

b. Blowing sand (150 to 850 μm particle size). These tests are performed to help evaluate if materiel can be stored and operated under blowing sand conditions.

Effects of sand and dust environments

Penetration of seals.

Degradation of electrical circuits.

Obstruction/clogging of openings and filters.

Physical interference with mating parts.

Fouling/interference of moving parts.

Reduction of thermal conductivity.

Interference with optical characteristics.

Overheating and fire hazard due to restricted ventilation or cooling.

Procedures

• Procedure I - Blowing Dust. Use Procedure I to investigate how susceptible materiel is to concentrations of blowing dust (< 149 Pm).

(1) Red china

(2) Silica flour

Silica sand

Procedure III - Settling Dust. Use Procedure III to investigate the effects of settling dust (≤105 Pm) on materiel (usually electrical) in sheltered or enclosed areas with negligible airflow

quartz, silica,

salts, fertilizers, organic fibers, etc.

Sand and dust composition.

WARNING

Refer to the supplier's Material Safety Data Sheet (MSDS) or equivalent for health hazard data.

Exposure to silica flour can cause silicosis; other material may cause adverse health effects