1. Sensitivity of leak recognition by the WLM-SYSTEM Noise development of leak Slight pressure change Flow direction change

2. Leak detail – noise characteristic Noiselevel on breakthrough 3200 Noiselevel 5h later 1850 Noiselevel 20h later 1550 Noiselevel before 1200

3. Dependencies of this leak Leak was approx. 250m from the probe. See the leak in development (in range of 0.04 to 0.16l/s  0.5 to 1.7cm/s Night analysis won’t give a hint on the distance of leak to WLM- Sensor; water into water  less noise is generated Direction change of flow shows position of leak from WLM-Sensor Leak gives only a high noise on breakthrough – the longer the leak exists the lower the noise –Advantage of permanent measurement! 20h later nearly no hint due to the leak noise, only in combination with flow and pressure gives significant indication