Azbil Model HPF-D040 Liquid Leakage Fiber Unit PFA jacket affords outstanding ease of routing. You can use this unit in an explosion-proof atmosphere because the cable is optical fiber. The unit has a space-saving switch head height of only 9.9 mm and can be used in explosion-proof environments because the cable is optical fiber (carefully check the explosion-proof regulations for location, application, and equipment prior to use). Azbil recommends using the Model HPF-D040 Liquid Leakage Fiber Unit with the Model HPX-AG04 amplifier with output latch. This function effectively detects a small leak of volatile liquid and in early zone/area detection.