10 



A MOISTURE TESTER FOR GRAIN, 



rubber stopper carrying the thermometer is inserted it can be readily 

 determined whether the mercury bulb of the thermometer is properly 

 adjusted in the oil, as showii in figure 9. Place the flask in the 

 proper compartment of the tester and proceed in a similar manner 

 with the remaining samples. 



The correct adjustment of the thermometer is a factor which must 

 not be ignored. If the mercury bulb of the thermometer is too near 

 the bottom of the flask the percentage of moisture will be too low. 



For the same reason it is im- 

 portant that there be some 

 uniformity in the length of the 

 mercury bulbs of the ther- 

 mometers, which should be ap- 

 proximately three-fourths of 

 an inch. 



As the thermometer is being; 

 inserted, glance along the sida 

 tube of the flask to make cer- 

 tain that it has not become 

 stopped by the lodgment of 

 some particle while emptying 

 or fining the flask. If the sid* 

 tube is not open to permit the 

 free escape of the rapidly form- 

 ing steam the pressure during 

 the heating will become suffi- 

 cient to blow out the stopper 

 and thermometer, or possibly 

 to burst the flask. 



When the flasks have been 

 filled and placed in the com- 

 partments of the tester, con- 

 nect the side tubes of the 

 flasks by means of the No. 3 

 rubber stoppers with the thimbles of the glass condenser tubes which 

 extend down through the cold-water tank, so that the moisture which 

 is liberated from the grain or other substance will be condensed and 

 collected in the graduated cyhnders beneath the tank. Figure 2 

 shows the correct manner of adjusting the various parts of the appa- 

 ratus. 



Place the cover over the flask, then ignite the gas, adjusting the 

 flame so that it will require about twenty minutes to reach the tem- 

 perature prescribed for the substance being tested. When the desired 



[Cir. 72] 



Fig. 9. 



-Distillation flask, showing the correct adjust- 

 ment of the thermometer. 



