Hi Brodin,
I have asked the firma who made this product for an application note how to use this.
Up to now I do not have an answer.
If I get one I will put it here,
I have looked to a simular one.
I found that when you take a operational amplifier with a high input impedance connect it as an inverting amplifier
connect at the input resistor the DET- .
The DET+ and the GND connect that to the 0 volt of the amplifier
circuit.
The gain of your system you have to findout youself.
Choose one so that you have a voltage output of about 3 volts in your working area.So the PIC ship has a good resolution of your problem.