The rain test is conducted to determine the effectiveness of protective covers or cases in preventing the penetration of rain, and the capability of the test item to satisfy its performance requirements during and after exposure to rain. Examples of some problems that could occur as a result of exposure of materiel to moisture and rain are:

1. Degradation of strength.

2. Corrosion of metals.

3. Deterioration of surface coatings.

4. Malfunction of electrical components.

The TDS Recon is tested for 40-minutes with a droplet-size of 2 to 4.5 mm at a pressure of 40 lbs./in². Prior to the test, the samples go through a hot-soak of 25 C (78° F) for 4-hours.