Old radiator temperature switch

Hi

I have an old radiator in my apartment with a giant metal wire and bar coming out of it, The radiator gets hot for a bit than once a temperature is met in the apartment it shuts of (maybe)

Does that device measure temperature? with one wire?

I will use an arduino to measure the temperature across the room, than send the info to an arduino at the knob. leaving the knob at only one setting.

How would I send a signal to flip the switch inside the knob to turn the radiator on and off?

I can take it apart a bit more but might have to shut off the water.

Thanks

You're correct. The device on the floor, first picture, is the temperature sensor and it controls the valve. The "Cable" most likely contains some fluid that is expanding at high temperature and lovers the throughput of hot water by the valve.

What is the real position of the sensor? A very common mistake is mointing the sensor in an unproper place.

I'll say, drop the idea controlling that radiator by an Arduino. The mechanism to the valve needs considerable force to operate.

It's called a capillary tube and like contains mercury. Very common device.

Paul