You have to pull an extra wire from the sensor’s input voltage to your Arduino’s AREF pin, so you know what the actual voltage at the end of the cable is, so you can estimate the 10-90% range.

Another pin you can use on the Nano to power it up is the 5V pin (located on Pin 27, close to the VIN pin at the end of the board). This pin mostly serves as a power output pin that supplies power ...