The Beverage Doctor portable pen style pH meter is an excellent value, considering all of the features it comes with. It is very accurate with a resolution of 0.01 pH. It is entirely waterproof, made of high quality components and includes automatic temperature compensation (ATC). The probe is designed to be easily and affordably replaced when needed. The cap seals perfectly over the probe to prevent it from drying out and decreasing its lifespan.
This unit features three point calibration: To get accurate readings over the complete range you really need 3 point calibration. This particular design is very easy to calibrate and you just press one button to calibrate.
The Beverage Doctor is a great device at an amazing price!