New or improved method of and apparatus for use in testing and constructing radio apparatus and other devices and various materials to withstand meteorological extremes

摘要

571,294. Testing radio apparatus. AIR CONTROL INSTALLATIONS, Ltd., and CLIFFORD, G. E. Oct. 4, 1943, No. 16234. [Class 40 (v)] [Also in Groups X and XIX] Apparatus for observing the performance of radio and other apparatus or materials under conditions simulating meteorological extremes of the order experienced by aircraft at high and low altitudes comprises a cabinet divided into five chambers in which (1) the article to be tested ; (2) control instruments and switch gear; (3) heating, cooling and moistening elements 10, 11, 12 and an air fan 15 ; (4) a water tank, air compressor 22 and receiver 23 ; and (5) a refrigerator compressor 25, and motor 26 for the air compressor and fan are respectively housed. The fan causes air to circulate from the testing chamber 1 through a duct 9 containing water sprays 12, an eliminator 13, and either over a heater 10 or cooling coils 11 according to the position of dampers 16 before extraction through a connection 14 and return through a duct 17 and perforated plate 18 to the chamber. Or the air may be byepassed through a duct 19 to duct 9 in the open position of dampers 20. An immersion heater is provided in the tank supplying the water sprays. Control apparatus, which may be set in motion by push-button for producing desired cycles of temperature, pressure and humidity conditions of variable duration such as result, e.g. in fog or glazed frost formation at high altitudes comprise electric and pneumatic controls operated as by a cam controller driven by a constant speed motor and by switch gear influenced by controllers associated with dry bulb and dew point thermometers on opposite sides of the water sprays. An exhaust pump may be included to provide sub-atmospheric pressures. Signal alarms or lights may operate before and after the working cycles and to indicate various phases of a cycle ; the temperature, pressure and humidity within chamber 1 may be recorded.