Up towards the mid 80s h2o ended up being detected with spot probe sensors. These devices might consist of sometimes an etched PCB or even 2 metal electrodes. Sensing concerning water ended up being complete with your DC voltage in one sensor while shopping for your return alert in the different. Delivering zero reunite sign is observed in all get back sensor, little h2o is found. The problem using this setup ended up being erosion regarding the sensors because of electrolyses and the limited area of water detection, water may movement away from on sensors and not get detected till far too late.