Panasonic EX-F70 sensor is equipped with a NORMAL indicator (green) which lights up when mounting correctly, and a FAULT indicator (red) which lights up when sensing the leaked liquid or when mounted incorrectly (forgetting to mount exclusive mounting bracket). So, the operation can be checked easily. Panasonic EX-F60 sensor enclosure and the cable sheath are made from PFA which is highly resistant to chemicals. Accurate sensing is achieved even if there are leaks of chemicals such as sulfuric acid, hydrochloric acid or ammonia. The unique effect of capillarity enables reliable detection of small leaks and viscous liquids. When a leak occurs, the beam from the beam-emitting part scatters through the leaked liquid and is not transmitted to the beam-receiving part. This slim (10 mm 0.394 in) side-mounting sensor is especially good for use in confined spaces. No need for sensitivity adjustment with adjuster, so initial mounting is easy. If the sensor is not mounted correctly, if the cable is broken or disconnected, or if the sensor is not operating correctly, the output is the same as when the beam is not received (LEAK). Design deals with human errors such as, forgetting to mount, etc.