This test is performed on cables intended for routing through watertight bulkheads. Such cables must be particularly resistant to longitudinal water flow to prevent potential damage to internal systems.
Pressurized water is applied at one end of the cable specimen, into the cable interior. A dry reservoir is placed below the opposite end of the cable to collect any water that leaks through the cable construction. After a specified time the water flow is cut off and the volume of water collected is measured. The collected water volume is compared to the applicable maximum limit as defined in the standard.