pH circuit designs that are available on the Internet today are antiquated and use a significant number of overly complex analog components. Atlas Scientific has reinvented and refined the pH Circuit of yesteryear. The Atlas Scientific pH Circuit is our fifth generation pH Circuit. The Atlas Scientific pH Circuit enables the engineer to easily incorporate scientific grade pH monitoring into your embedded system using modern components and communication methods. With a wide operating voltage (3.3V to 5.5V) and a simple asynchronous serial communication protocol, this is an easy to use pH Circuit specifically designed for modern embedded computer systems. The Atlas Scientific pH Circuit is designed for both continuous and intermittent readings. After calibration, the pH Sensor can be immersed in a liquid and operate continuously for 12 months before recalibration is recommended.