AEROGRAPHER'S MATE 3 & 2 



AN/GMQ-29( ) 



The AN/GMQ-29( ) Automatic Weather Sta- 

 tion, figure 4-10, accumulates and displays 

 meteorological data for support of air station 

 operations and for use in forecasting. It is 

 intended for installation at air stations where 

 sensing equipment can measure weather con- 

 ditions at or near the runway area and transmit 

 the data gathered over a single audio channel 

 to the operations area for display. 



The station consists of two major compon- 

 ents. The first is the sensor group with 

 meteorological sensors and data transmission 

 electronics. The second is the Converter Dis- 

 play Group, with data reception electronics, 

 digital displays, and chart recorder. (See fig- 

 ure 4-11.) 



Description of Components 



The sensor group consists of the signal 

 conditioner, transmitter, and the meteorological 

 sensors. The conditioner, transmitter, and 



barometric pressure sensor ML-642/GMQ-29( ) 

 are housed in a weatherproof cabinet upon which 

 some components are mounted. The other 

 sensors are located as follows. 



AIR TEMPERATURE SENSOR (ML-641/ 

 GMQ-29( )). — This sensor consists of a re- 

 sistance element probe mounted in an enclosure 

 which provides solar radiation shielding and 

 protection from precipitation while permitting 

 a free flow of air. (See figure 4-12.) The air 

 temperature sensor is normally mounted with- 

 in 15 feet of the transmitter. 



DEW-POINT SENSOR (ML-643/GMQ-29( )).— 

 The dew-point sensor is a heated resistance 

 probe installed in a chamber which permits 

 adequate self aspiration while protecting the 

 sensor from solar radiation, wind, and rain. 

 (See figure 4-13.) Normal installation of the 

 dew-point sensor is within 15 feef of the trans- 

 mitter. 



RAINFALL SENSOR (ML-558/GMQ-14( )).— 

 This system is discussed later in the chapter 

 under rain gages. 



209.393 



Figure 4-10.— AN/GMQ-29( ) Automatic weather station. 



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