ARD2-2228 and translating raw data

Hi everyone,

I'm kind of new to Arduinos and have set up what I though would be a simple project for my year 12 students. I tasked them with creating a simple thermometer but the only temperature sensor I could get my hands on from my local electronics store was a ARD2-2228. It has 4 pins, 1 analog out, 1 digital out, positive and ground.
The problem I have is that I can't seem to find on the data sheet whether it needs a resistor or what kind of resistor. The values I get from the analog pin are bizarre numbers that actually decrease as the temperature increases (as i breathe on the sensor or put it in a warmer environment).

The sample code on the data sheet just shows you how to set up the digital pin to turn on a LED if the temp recorded is above an internal level that can be set using a tiny potentiometer on the chip.

I've looked around at other posts here and on the web that give temp conversions, map ranges etc but none of the code I've found seems to give accurate results. Can someone help me figure out what I need to do in order to get this sensor working or am I better off getting rid of it and ordering a simple digital temp sensor?



Sorry here is the data sheet:

That sensor, as U have determined, is an NTC.
U'll find many example examples here on the forum.

..or simple ?:
Do analog readings @ 3..4 known temperatures. Then do regression to find a suitable function to use in your code.
May be for your students ? They will exper.. how an NTC behaves