Figure 0-1. Wrist-flip action. 



voir is being frozen. Next, quickly remove the 

 thermometer from the freezing sohition and tap 

 the bulb end of the thermometer while the 

 instrument is in a righted vertical position 



(fig. G-3). 



This procedure is usually 100 percent success- 

 ful in the instances when it must be applied 

 and even though rather vicious tapping might 

 be necessary, the fragile area of the thermom- 

 eter is not unnecessarily subjected to damaging 

 action in this attitude. Although there may be 

 other methods, this has been found to be the 

 only really safe technique to achieve manipula- 

 tion of thermometers which have not had exer- 

 cise for a prolonged time and as a result fail 

 to drain. 



Figure G-3. 



Tapping action with rubber-headed 

 hammer. 



Figure G-2. Simultaneous cooling and heating action. 



Step 4. Once the mercury is dislodged, exer- 

 cise the thermometer extensively between pe- 

 riods of immersion in a hot water bath. Toward 

 the end of the exercising procedures when the 

 manijDulation is almost complete, freezing all 

 mercury in the reservoir will not do any harm 

 and in some cases will help mix the impurities 

 in the mercury so thoroughly that the condition 

 will not reoccur if the thermometer is exercised 

 regularly. 



All malfunctional reversing thermometers, 

 except the FTD type, should be returned to the 

 U.S. Naval Oceanographic Office, Thermometer 

 Calibration Laboratory, for manipulation and 

 recalibration by experienced personnel. 



G-7 Exercising Reversing Thermometers 

 after Manipulation. — The importance of exer- 

 cising thermometers after manipulation cannot 

 be over emphasized since it is difficult to tell 

 immediately whether the correction of a mal- 

 functional reversing thermometer was entirely 

 successful even though visual inspection leads 

 to this conclusion. If the preexamination iden- 

 tification of the cause was a corrective malfunc- 

 tion, and the manipulation was successfully 

 executed, the recurrence of a malfunction 

 should not arise in a good thermometer that is 

 properly treated thereafter. To verify the suc- 

 cess of manipulation procedures, however, 

 thermometers so treated should begin to be ex- 



G-3 



223-812 O - 68 - 6 



