... water meter for water\liquid level 2.Ac or Dc power supply optional 3.Apply to all kinds of medium 4CE.UL.RoHS Ultrasonic ... working principle: the probe launch a bunch of ultrasonic pulse to the object, ultrasound is reflected by the object surface, then ... trough, pool, well, Drains, measuring boxes, granaries, silo, etc.Specifications1.Power supply: DC24V(±10%),0.1A ; AC220V (±20%), 0.05A2.Pricision ...