To assess the concrete surface absorption characteristics. The rate of flow of water per unit area into a concrete surface when subjected to a constant head of 200 mm is measured.

The apparatus consist of :
* Supplied with reservoir, capillary tube, scale and connection to cap
* Supplied with cap for clamping on to smooth surface and manufactured from clear plastic incorporated a rubber seal complete with clamp mechanism.
* Mounted on a stand complete with rubber tubing and cup
* Bore glass tube 1.9mm diameter and 240mm long mounted on scale and support board
* The scale on a support board reading in mm
* Test specimen up to 150 mm concrete cube
* The test cap for rough surface incorporated with knife edge contact