A sail switch, vane switch or flow switch is a mechanical switch that is switched on or off in response to the flow or non-flow of a fluid such as air or water. A sail switch typically operates through the use of a paddle which gets displaced due to the force of fluid moving past it. Sail switches find application in the detection of fluid flow and measurement of fan speeds. A sail switch might be used to protect a central heating system electric heating element from being energized before the air flow from the blower is established. Sail switches might also be used to alarm if a ventilation fan in a hazardous location fails and air flow has stopped.
Famous quotes containing the words sail and/or switch:
“Light boats sail swift, though greater hulks draw deep.”
—William Shakespeare (1564–1616)
“Uncritical semantics is the myth of a museum in which the exhibits are meanings and the words are labels. To switch languages is to change the labels.”
—Willard Van Orman Quine (b. 1908)