32 CREAMERY BUTTER MAKING 



It has been learned that the vokmie of the graduated 

 part of the neck is 2 c.c. Each section of the tester is 

 made to displace i c.c, when immersed in the liquid, 

 hence the two sections will just fill the scale if the latter 

 is correct. 



The method recommended below for calibrating cream 

 bottles may also be used with milk bottles. 



Calibrating Cream Bottles. According to Hunziker,* 

 the most satisfactory method of calibrating cream test 

 bottles is as follows (see Fig. ii): Fill the bottle to 

 the zero mark with w^ater. Remove any drops adhering 

 to the inside of the neck with a coiled piece of filter or 

 blotting paper. Now slowly add measured amounts of 

 water from an accurate burette graduated to at least o.i 

 c.c. Every o.i c.c. of water run into the neck is equiv- 

 alent to 0.5% on the scale of an 18 gram cream bottle and. 

 1.0% on a 9 gram cream bottle. That is, with an 18 

 gram 30% bottle, 6 c.c. of water would be required to 

 exactly fill the scale on the neck. 



In calibrating milk and cream bottles, different parts 

 of the neck should be tested as well as the neck as a 

 whole. 



Calculating Speed of Tester. The speed at which 

 a tester must be run is dependent upon the diameter of 

 the wheel carrying the bottles. The larger this wheel 

 the fewer the revolutions it must make per minute to 

 efifect a complete separation of the fat. 



In the following table by Farrington and Woll the 

 necessary speed per given diameter is calculated: 



•Bulletin No. 145, Indiana Experiment Station, 



