This International Standard proposal specifies technical requirements and test method for temperature sensor in radiosonde. This International Standard is applicable to the temperature measurement traceable to SI unit in boom sensors according to variations of pressure and air speed under the simulated conditions of upper air. This proposed standard will mainly provide a) Terms and definitions b) Technical specification for test instrumentations. c) Test procedure of temperature measurement sensors according to pressure and air speed. d) Uncertainty evaluation of the test procedures. The compensation of solar radiation effects to the temperature sensor will be described in a separate Standard.