Environmental Tests of Meteorological Radiosondes Including Dynamic Temperature and Humidity Simulation in a Wind Tunnel

Abstract : An experimental investigation of the performance of meteorological radiosondes subjected to controlled variations of humidity and temperature in an environmental wind tunnel is described. Dynamic variations in temperature between -60 and 40C and in relative humidity between 0 and 100 percent, representative of those encountered in atmospheric flight were simulated by injecting liquid nitrogen or steam, respectively, into the wind-tunnel air supply. Tests were conducted at free-stream velocities of 15 and 75 ft/sec duplicating the average ascent and descent rates, respectively, of balloon-borne rawinsondes and dropsondes. Free-stream static pressures appropriate to the 300- and 700-mb levels were employed.