To determine the resistance to the passage of simulated rain by fabrics being rubbed and rotated. Water which penetrates the fabric is measured and the test specimen weighed to determine the amount of water absorbed. The tester consists of 4 specimen holders of 100 mm diameter placed over cups with a rotating member rubbing the underside. Rain is produced using filtered water under pressure and is allowed to fall from a height of 150 cm through 300 drop-forming devices.

Optional centrifuge to remove excess surface water from tested samples for evaluation.