If it's a 4-20mA sensor, then you should really use a ~128ohm (Mega) or 51ohm (Uno) load resistor and use 2.56volt Aref (Mega) or 1.1volt Aref (Uno). Not the 273ohm that I see on that link.
Using the buildin Aref voltages eleminates the need for a accurate/stable supply voltage.
Diagram and more info in post#5 here: ProSense PTD25-20-0200H pressure transmitter, - Sensors - Arduino Forum
Mapping values depend on which sensor you have.
You need to know at which temp the sensor outputs 4mA, and at which temp te sensor outputs 20mA.
Leo..