Automatic Water Level Control for Tanks

Issue 4 and Volume 78.

Automatic Water Level Control for Tanks A new device known as the Johnson Tank Level Controller and made by Edward E. Johnson, Inc., St. Paul, Minn., automatically regulates the level of the water in the tank and avoids all danger of overflow. This is accomplished by the rising and lowering of mercury in a tube, counterbalanced by the pressure of the water in the tank. As this pressure varies by the rise and fall of the water level so does the height of the mercury column in the controller. The controller regulates by this means the start and stop buttons of the electric motor actuating the pumps. As the water lowers in the tank, the mercury contact tube approaches contact. When this occurs an electric circuit is closed, thereby energizing the relay, starting the motor, cutting out the red low water signal, and lighting the green signal, indicating that the…

Subscribe to unlock this content

Subscribe Now