I searched on the Net, and according to the Wiki of arch, I should first install lm_sensors. Then, I ran sensors-detect. After doing that, I ran sensors, and got the following output:
Adapter: Virtual device
Core 2:****** +40.0°C* (high = +80.0°C, crit = +90.0°C)
As you can see, the result is not complete. My laptop is dell studio 1458, and the cpu is i3. I am supposed to modify the sensors.conf to add something so as to make sensors show the rpm of my fan. But the problem is I don't know my chip's name. I guess my chip's name should be coretemp, but there is no coretemp in the conf.
My final purpose is to control down the fan, and I am in wheezy.
What should I do?