FROM THE PRACTICAL VIEWPOINT 



If such cooling in the tank does take place, then 

 the length of time for which the recording mark 

 remains at the highest point is a correct indica- 

 tion of the time for which the hot milk is held. 

 If the cooling is performed entirely outside the 

 holding tank, then allowance must be made for the 

 time necessary for the milk as drawn from the 

 tank to fall below the point where the thermome- 

 ter bulb is inserted into the milk. It is plain that 

 the making of the record by the recorder pen will 

 continue as long as the bulb remains in the hot 

 milk. Thus, if the highest temperature were re- 

 corded for forty-five minutes, and it required twen- 

 ty-five minutes for the milk in its discharge to fall 

 below the recorder bulb, then the actual holding 

 time for all of the milk would be but twenty 

 minutes. 



When the continuous holding process is used, it 

 is desirable that a recorder be attached to the out- 

 let of the heater, and that another be placed in the 

 outlet pipe from the holder. If the charts on these 

 two recorders are both set at the correct hour of 

 the day then it is easy to calculate the duration 

 between the time of the first discharge of hot milk 

 from the heater and the first discharge from the 

 141 



