62 



Testing Milk and Its Products. 



tion. Tests have often been lost by the end of the neck 

 catching at the center, the bottles thus failing to take 

 an upright position when the whirling stops. 



71. The exhaust steam pipe of turbine testers should 

 not have too many turns in it or be much reduced in 

 size from that of the opening in the tester. A free es- 

 cape of the exhaust steam is necessary to prevent the 

 steam collecting in the test bottle chamber and over- 

 heating the test bottle when whirled (41). 



The cover of the tester should have an opening pro- 

 vided with a sliding damper or some arrangement by 

 which it can be closed when desired. If whole milk or 

 cream is being tested, this hole should be open so that a 

 draft of air may enter the test bottle chamber during the 



whirling, and force 

 the steam out of 

 the bottle cham- 

 ber into the ex- 

 h a u s t pipe. If 

 skim milk is being 

 tested, the open- 

 ing in the cover 

 should be closed. 

 This shuts off the 

 draft of air, and 

 the exhaust steam 

 heats the test bot- 

 tles during whirl- 



FIG. 23. Type of Babcock electrical testers, ing to 200 F. in 



some cases. This high temperature aids in separating 

 the fat in skim milk and gives fairly correct tests of 



