Dual level liquid sensor circuit design

This level liquid sensor electronic circuit diagram is based on a common Ca3410 operational amplifier IC . This level liquid sensor electronic circuit use two plates sensors ( two probes ) , one for the high level an one for low level .
If the level of the liquid is not in the adjusted range the LED will glow . The circuit require just a CA3410 operational amplifier and other few common components . This dual liquid level sensor require a 15 volt DC power supply circuit .