Â­TÂ­here are many different ways to create a motion sensor. For example: 1  It is common for stores to have a beam of light crossing the room near the door, and a photosensor on the other side of the Â­room. 2  When a customer breaks the beam, the photosensor detects the change in the amount of light and rings a bell.
Definition of weir. 1  1 : a fence or enclosure set in a waterway for taking fish. 2  2 : a dam in a stream or river to raise the water level or divert its flow.
It is made up of two plants, one built just recently as part of an expansion. The facility upgrade added effluent filtration, filter dosing and backwash water tanks, and an influent flow equalization tank, along with a 100,000-gallon aeration tank and secondary clarifier.