Product Testing > Notes and Reviews > Fabric Testing > T29B: Water Penetration - Hydrostatic Head
AWTA TEST CODE
:
T29B
OTHER NAMES
TEST METHODS
AS 2001.2.17 BS 2823 DEF 5037-A18ISO 811
IMAGES
Close-up of Pressure Chamber and Specimen in Place
Hydrostatic Test Apparatus
APPLICATION
The method is applicable to all fabrics which are water repellent or have been coated to impart resistance to water penetration.
PRINCIPLE
The hydrostatic pressure supported by a fabric is a measure of its resistance to the passage of water through it. A specimen is subjected to a uniformly increasing pressure of water on one face until penetration occurs in three different places. The hydrostatic pressure at which water penetrates the fabric at the third place is noted.
SAMPLES REQUIRED FOR TESTING
The fabric sample should be approximately 1.5m2 in area. It should NOT have been cut within 2m of the lead end or tail end of the fabric piece, roll or lot.
INTERPRETATION
A minimum hydrostatic pressure is usually specified for fabrics resistance to water penetration. This is usually dependent on fabric end use, e.g. Defence Standard for raincoats requires 7.5 kPa minimum.
The test result should be compared with the specified value.
SERVICE TARGET
6 days.
COST
See Fee List.