Application Note: Swimming Pool Level Control

I never gave it much thought, but what happens to the displaced water when a hundred people jump into a large public swimming pool? It goes into a surge tank - of course.

This Greyline LIT25 Level Indicating Transmitter with ultrasonic sensor is installed in the basement of the Okotoks Recreation Centre in Alberta, Canada. The LIT's 4-20mA output is connected to a solenoid valve to control flow of makeup water into the surge tank.

In a system installed by Master Pools of Edmonton, Alberta, the Okotoks Rec Centre needs to maintain the surge tank water level above the pump intake and also to ensure that the pool level remains constant.

This concrete wall is actually the outside of the surge tank and the ultrasonic sensor is mounted on conduit inside at the top of the tank. The plexiglass manhole window gives operators a view of water level as excess water is being discharged to the municipal sewer.