Water and Wastewater Terms Beginning L
A B C D E F G H I J K L M N O P Q R S T U V W Y Z
level control
A float device (or pressure switch) that senses changes in a measured variable and opens or closes a switch in response to that change. In its simplest form, this control might be a floating ball connected mechanically to a switch or valve, such as is used to stop water flow into a toilet when the tank is full.