But it has 3 wires . 2 of the wires shows about 42kohms at room temperature and the others show in the megaohm range or open circuit. As i heat it, the resistance drops e.g. it dropped to 34kohms at my experiment.
A basic ntc circuit would be as below - only 2 connections to the ntc.
You say you are measuring voltages on the circuit board connector to the sensor but you do not relate them to the ohms test details you originaly posted .
Good, that you finally mentioned this. Seriously, you can't know about the sensor type without watching it in operation. Beside RTD and NTC or silicon PTC sensors, there are also IC sensors with different kind of output signals, e.g. analog voltage, frequency, digital data. Tracing the said output terminal can give a first hint about the sensor type.
I have seen such sensors where a LM35 will be immersed in heatsink compound packed inside similar copper or brass tubes for better heat transfer and these will have 3 wires out. But i am not sure about your sensor as you'll have to carefully open it can confirm if possible.
I have seen such sensors where a LM35 will be immersed in heatsink compound packed inside similar copper or brass tubes for better heat transfer and these will have 3 wires out. But i am not sure about your sensor as you'll have to carefully open it can confirm if possible.