Abstract: A concert between the pressure transmitter and the temperature sensor by using the air bottle is introduced. The pressure and temperature of the gas under the condition of equal volume are measured. By using the extend method, one can estimate the lowest temperature （ i. e. , the absolute zero degree） of the ideal gas. By substituting the original glass tube for measuring the volume and the mercury thermometer measuring the temperature, we use a new experimental installation for measuring the absolute zero degree. Thermodynamics phenomenon can be observed obviously and the value of absolute zero degree can be observed accurately.

Key words: pressure sensor, temperature sensor, absolute zero degree