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.
Effluent is an outflowing of water or gas from a natural body of water, or from a manmade structure. Effluent, in engineering, is the stream exiting a chemical reactor. Effluent is defined by the United States Environmental Protection Agency as wastewater - treated or untreated - that flows out of a treatment plant, sewer, or industrial outfall. Generally refers to wastes discharged into surface waters.
A waste weir provides a means of removing excess water from the canal, and provides a means of draining a section of the canal for repairs, for winter, or in anticipation of flooding. Because rising canal waters could overflow the banks, eroding them and causing a break in the canal, waste weirs were an important safety feature of early canals.