APS testing guideline
An important on-site test is conducted by the IKT institute for subterranean infrastructure. The leak test is performed as follows: A sample section of about 30 x 20 cm is inspected by an independent expert. The IKT checks the leak tightness of three samples as shown in the images. The red drop consists of local utility water and should have a diameter of about 45 mm. The evaluation is based on the passage of testing liquid through all three sample sections. The two possible results are TIGHT and NOT TIGHT.