A system, method and apparatus for determining a physiological condition within a mammal based on pH and/or temperature measurements. In one aspect, the invention is an apparatus for measuring a physiological condition within a mammal comprising: a probe for insertion into a body lumen of the mammal, the probe housing a first circuit board operably coupling a pH sensor for measuring pH and generating a pH signal indicative of the measured pH, a memory device storing parametric data unique to the pH sensor, and a first interface connector located at a proximal portion of the probe a handle for manipulating the probe, the handle housing a second circuit board operably coupling a microprocessor for processing the pH signal, and a second interface connector the probe connected to the handle in a manner that allows the probe and handle to be repetitively engaged and disengaged from each other.
