Sludge blanket sc200 sensor
You will have to pull out the instructions and set your parameters again. Specifically, input the depth of the tank where the sensor is located then choose SL or SH, depending on whether you want to track sludge height at the bottom or the depth of free water. And don't forget to set your analog output if using one.
As it happens, I have to replace two sludge blanket measurements in a thickener. What brand is your device and are you satisfied with it?