Electronic Sensors, Inc. (ESI) "Level Devil" American-made tank monitors and tank-monitoring systems monitor bulk fluid tank levels of most fluids -- industrial chemicals, cyrogenics, fuels, lubricants and oils (including lube and oil services), waste oil recycling, agricultural chemicals and food-processing gasses and fluids, via cellular, landline, satellite, WiFi and serial (RS-232) remote communications and local displays and alarrms, with ultrasonic, radar, mechanical, capacitive, pneumatic and hydrostatic pressure sensors. LevelDevil ®