What methods of temperature controller to control temperature?

Temperature controller is to control the temperature change of equipment instrument, control the temperature of the air conditioning room is in commonly 18 Between 28 ℃. Is the main component of the corrugated pipe, thermal bags, eccentric structure, etc. Many are just know temperature controller can control the temperature change, but don't know is how to control concrete. Generally speaking, the method of controlling the temperature thermostat has two kinds, one is controlled by the temperature change of the object being cooled, mostly use the steam pressure type temperature controller; The second is controlled by the temperature change of the object being cooled to, with electronic temperature controller. And on the inside of the content of the classification of the thermostat, the above two kinds of temperature controller can also be specific classification. Steam pressure type temperature controller and liquid expansion thermostat, gas adsorption type thermostat, metal expansion thermostat are mechanical thermostat. Type and steam type temperature controller is divided into gas, liquid and gas mixed type of the three types of household air conditioner thermostat most of this kind of thermostat, electronic temperature controller is divided into resistance type and electric type two kinds. About the content of the thermostat so everyone had a deeper understanding of temperature control? Hope to be of help.