Chapter 4 -TEMPERATURE, HUMIDITY, AND PRECIPITATION 



209.401 



Figure 4-18. — Tipping bucket rain gage, with door 



open showing the two-compartment tipping bucket 



on its pivot. 



contact is established within the switch, causing 

 an electrical impulse to be sent to the AN/ 

 GMQ-14 recorder, thereby tripping a relay. 

 Each time the signal is received, the rain- 

 fall counter registers the 0.01 inch of rain, 

 and the rainfall recording pen at the right side 

 of the recorder moves laterally one step. The 

 pen has a range limit of five steps before 

 reversing its direction of motion. 



The AN/GMQ-23( ) presents both a digital 

 display and recorded trace of rainfall. The 

 tipping motion switch closures provide pulses 

 to be counted and stored in the rainfall sig- 

 nal conditioner for each .01 inch of rainfall 

 that occurs during the data frame (time period). 

 The content of the counter is transferred to 

 the display on command of the data transmitter. 

 The contents are used to update the rainfall 

 digital display and totalizer counter. The Analog 

 Recorder RO-447/GMQ-29( ) (discussed earlier 

 In chapter 3) is used to record the rainfall 

 amounts. It is recorded on the right side mar- 

 gin of the chart and as an event marker to 

 the left for each 0.01 inch of rain, with every 

 tenth mark (0.01 inch) reversing direction and 

 recording a mark to the right. 



Maintenance 



Inspect the tipping bucket assembly and the 

 measuring cylinder for corrosion or deteri- 

 oration. Ensure that the bucket moves freely 

 within the casting in which it is installed. When 

 replacing the bucket, ensure that the magnet 

 mounted on the tipping bucket is toward the 

 mercury switch (away from the inspection, 

 door). 



OCEANOGRAPHIC TEMPERATURE 

 SENSORS 



Sparseness and inaccuracy of data are among 

 greatest difficulties to be overcome in attempt- 

 ing to prepare accurate oceanographic forecasts. 

 To aid in obtaining this data, numerous pieces 

 of equipment have been designed to sense the 

 ocean temperatures, both at the surface and 

 below it. The Aerographer's Mate generally 

 does not operate these equipments, but may 

 come into contact with them on occasion. 



A brief resume of the types of oceano- 

 graphic sensors and their functions are de- 

 scribed in the following paragraphs. 



NON-CONTACT SENSORS 



One way of oceanographic data sensing is 

 the non-contact method. This method obtains the 

 sea surface temperature by use of infrared 

 equipment, such as the Portable Radiation 

 Thermometer PRT-4( ). It is designed to meas- 

 ure the infrared radiation from surfaces which 

 are difficult or impossible to measure by con- 

 ventional methods because of physical location 

 or other restrictive conditions. 



Another infrared device is the Airborne 

 Detection Thermometer. This is a completely 

 self-contained, non-contact airborne radiation 

 thermometer which automatically measures and 

 records the surface temperature of the sea. 



CONTACT SENSORS 



The second way to obtain oceanographic data 

 is the contact method. Both the airborne and 

 shipboard bathythermograph are used for this 

 method. These sets automatically obtain and 

 record ocean temperature data by the use of 

 expendable probes that are ejected from the 

 ship or aircraft. This ship version will re- 

 turn a temperature profile to a depth of 1,500 

 feet while the aircraft only returns a 1,000- 

 foot temperature profile. Both profiles are de- 

 picted on a recorder mounted in the ship or 

 aircraft. 



For more information on these various 

 oceanographic temperature sensing eqaipments, 

 refer to the appropriate technical manuals. 



NOTE: Changes to all column numbers and 

 entries on NWSC Form 3140/8 were received 

 too late for inclusion in this manual. Where 

 errors in column numbers appear, refer to the 

 U.S. Navy Supplement to FMH #1, Chapter 13, 

 Marine Aviation Observations for the most re- 

 cent amplifying instructions. 



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