This product was designed to meet the specific need to know when a liquid level has either risen too far or dropped too low. The Float Alarm is battery operated and simplicity itself to install. The device incorporates a low battery warning feature and an LED that flashes periodically to allow the user to be satisfied that the product is active. It also warns when the battery is beginning to run low.
When an alarm condition occurs the alarm makes a high pitched noise and flashes its LED every few seconds. The sound can be silenced by pressing the button on the unit, but the LED will continue to flash until the alarm condition is removed.
Typical uses are for the space between the inner and outer skin of an oil tank, or to warn of overfilling in a tank. It can also be used as a flood alert in a basement etc.
The Float Alarm is sold by Hytek (GB) Ltd. See http://www.hytekgb.com/