There are many applications where the interface between two immiscible liquids must be monitored or controlled. These may involve oil and water separators, wastewater disposal tanks and a multitude of chemical processes.

The LG series gauges can be used with a specially weighted float that will sink in the top layer and float in the bottom layer provided there is a specific gravity difference of at least 0.1 between the liquids. Other options such as the Magtech level switches and transmitters for interface control or even dual floats for both levels are common.

If a customer has a decanter or oil separator tank ahead of his wastewater plant, this can easily prevent him from dumping unwanted material to the treatment plant or effluent where major problems could develop. It is possible to cause environmental damage resulting in fines or worse punishment.