With the sensor removed from the cruit here is some readings.
There are 2 sets of copper legs ofc.
Neither set of copper legs are conected directly to ground. One goes through a 10 ohm resistor to positive terminal of sensor.
Copper legs don't have connection to one another besides their corresponding group.
When reading to ground 6M ohms is read. This is most likely through the transistor.
So I assume based on this model the the less resistance between the copper legs the more voltage is allowed to go through the transistor.
I traced it out with my DMM
LM 1-6 represent the copper legs. I didn't have anything good to represent them.