Water penetration tester
The water penetration tester , also known as Karsten's tube or water penetration tester according to Karsten, is a measuring device with which vertical to horizontal surfaces can be tested non-destructively for water absorption or water permeability.
It is mainly used in the building industry to test plaster (building material) or other building surfaces such as concrete, clinker or joints. The body is made of glass, consists of an open vertical cylinder and a chamber with a rim for attachment to the surface to be tested. It is attached with putty, butyl rubber (body sealant), etc. There are two designs, each for testing vertical and horizontal surfaces. The test principle is simple: the water penetration tester is covered with putty all the way around its edge and then pressed onto the test surface until the putty forms a seal between the wall and the edge of the chamber. If water is now poured into the open end of the cylinder, this exerts pressure on the surface in accordance with the water column formed. The tester can now observe whether the water level is falling and draw conclusions about the water absorption capacity or permeability of the surface. The water absorption ( water absorption coefficient ) of plaster can e.g. B. can be roughly determined by measuring the (negative) acceleration of the lowering of the water level.