This document specifies a test method in terms of calibration error for radiosonde temperature sensors sampled from a batch of mass production, with varying temperature in laboratory setups at ground level pressure. This document elaborates on:

a)       the technical requirements for test chamber and reference thermometers as essential laboratory setups to evaluate the calibration errors of radiosonde temperature measurement;

b)       a test procedure including the installation of radiosondes in the test chamber, the operation of laboratory setups and the comparison between radiosonde and the temperature references for evaluating calibration errors of radiosonde temperature sensors for a temperature range of −85 °C¹⁾ to 50 °C at laboratory conditions; at

c)        a method for evaluating the uncertainties related to the references and the radiosonde sensors for the measured radiosonde temperature calibration error.

NOTE            Calibration error of radiosonde treated in this document forms only a part of the error in radiosonde sounding measurements. Regarding the errors involved in radiosonde temperature measurement on sounding, it is necessary to consider various errors as shown in Table 2 of Reference [7]; this document provides only a partial evaluation in laboratory tests.