MorganS:
Yes and no. That chip seems to be a complete processor, much like the Arduino's 328P. Yes you can talk to it if it's been programmed to talk to you.For me, I'd try to find the actual sensor chip and its datasheet. If there's no sensor and the chip's analog inputs are used, then it's possible that you can do it on an Arduino anyway.
will while following the traces on the circuit board it appears that the sensor is fed 3v from the batteries. then the other end of the sensor is soldered to pin 15 on that chip the "PA5/AN4/VREF" pin. wouldnt it be easier to just do the analog conversion on the arduino? is that what the "PA5/AN4/VREF" pin does is read the voltage and convert that to digital?
also there is no datasheet on this meter and the sensor is what appears to be 2 properly spaced pieces of titanium