Details about PH Electrode Probe BNC + Liquid PH0-14 Value Detect Sensor Module for Arduino
US $28.89 New in Business & Industrial, Electrical & Test Equipment, Electrical Equipment & Tools. To make it work you will write some code. Connect to analog pin of arduino to read a voltage index. Offset and pH level alert pots onboard are nice idea but didn't work out to be very useful for me.