AEROGRAPHER'S MATE 3 & 2 



24-HOUR MAX AND MIN TEMPERATURES 

 (COL. 66 & 67). — Col. 66 will be the maximum 

 value recorded in col. 47 for the day. Col. 

 67 will be the minimum value recorded in 

 col. 48 for the day. Note that the value on 

 the line captioned "1" in cols. 47 and 48 is 

 for a period extending prior to midnight (LST); 

 consequently this value is disregarded in deter- 

 mination of the 24-hour maximum and mini- 

 mum temperatures. 



24-HOUR PRECIPITATION (COL.68). — En- 

 ter the total precipitation (water equivalent) 

 for the 24 hours ending at midnight to the 

 nearest 0.01 inch. 



24-HOUR SNOWFALL (COL.69). — Enter the 

 total amount (unmelted) of solid precipitation 

 that has fallen in the 24 hours ending at mid- 

 night LST. 



SNOW DEPTH (COL.70). — Enter the depth 

 of solid precipitation and ice on the ground 

 at 1200 GMT or, in areas other than the con- 

 tiguous United States, a time modified as nec- 

 essary to meet regional needs. Entries are 

 made to the nearest whole inch. 



PRECIPITATION, THUNDERSTORMS, AND 

 OBSTRUCTIONS TO VISION (COL. 82/86). — En- 

 ter form of precipitation occurring at the sta- 

 tion. All entries will be in accordance with 

 the appropriate tables in FMH-1 or Table 10-1 

 of this manual. 



BEGAN' and ENDED (COL. 83 & 84). — En- 

 ter the local standard time that the precipi- 

 tation entered on the same line in column 82/ 

 86 began (COL. 83) and ended (COL. 84). 



When any of these phenomena is occurring 

 at midnight, enter "Cont." in column 84 for 

 the day ending at midnight, and in column 83 

 for the day beginning at midnight. 



NWSC FORM 3140/8 Entries 



SEA WATER TEMPERATURE. — Enter sea 

 surface water temperature to the nearest tenth 

 degree Celsius. Corrected readings from the 

 condenser intake may be used provided such 

 corrections have been determined by a series 

 of comparative bucket-condenser readings for 

 the ship's current speed. 



The method for taking bucket observations 

 is explained in FMH No. 1. 



AN/GMQ-29( ) and AN/GMQ-14( ), 

 Temperature, Dew-point, and 

 Precipitation Recording Charts 



The AN/GMQ-29( ) recording chart records 

 only precipitation and wind (which was dis- 

 cussed in chapter 3), while the AN/GMQ-14( ) 

 records temperature, dew point, and precipi- 

 tation. The AN/GMQ-29( ) chart should be 

 changed at midnight (LST) on the 1st of every 

 month, and as often thereafter as necessary. 

 The charts should be annotated in accordance 

 with the following: 



1. At the beginning and end of each chart 

 enter the station name, date, and time to the 

 nearest minute (LST) when the chart was put 

 on or taken off. 



2. Time-check the chart at every 6-hourly 

 observation, with the time to the nearest minute. 



3. When the chart is adjusted for time, in- 

 dicate the adjustment on the chart by entering 

 an arrow at the point of the adjustment and 

 write 

 row. 



the time of the adjustment near the ar- 



4. Time check the chart upon notification 

 of an Aircraft Mishap. 



5. For each disruption or discontinuity, such 

 as a power failure, equipment failure, etc., 

 enter on the chart at this point the reason and 

 time of the interruption. When returned to ser- 

 vice, correct the chart for time and enter a 

 time check. An appropriate entry should also 

 be made in block 90 of MF1-10. 



6. Enter a time-check at the first observa- 

 tion of the day at stations not operating 24 

 hours per day. 



THERMOMETERS 



Thermometers are classified according to 

 their operating principles and their purpose. 

 In this section only the liquid-in-glass ther- 

 mometers are discussed. 



Llquid-in-glass thermometers are designed 

 on the principle of differential expansion. The 

 fluid used In the thermometer expands and con- 

 tracts at a different rate than the glass tube It 

 is contained in. By etching an appropriate scale 

 on the tube we can measure this difference in 

 expansion and thereby determine the change in 

 temperature. 



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