A fluid detection system by which the presence or absence and identity of fluids may be detected within confined areas, such as those existing within underground storage tank systems and in which fluids may accumulate. The fluid detection system includes a probe assembly having circuitry which determines...http://www.google.fr/patents/US5202667?utm_source=gb-gplus-shareBrevet US5202667 - Electric leakage detector for underground storage tank systems
Electric leakage detector for underground storage tank systems
