36 DAIRYING 



most durable as well as the most easily cleaned. Some separators 

 do good work when all conditions are constantly watched and 

 kept up to or exceed the instructions of the manufacturer, but 

 a slight variation from these, such as a low speed, high feed, low 

 temperature of milk, etc., seriously affect the test of the skim 

 milk and cause a loss of cream. Several tests of a separator 

 should, therefore, be made, before final judgment is passed on it. 

 These tests should cover not only the skimming qualities of the 

 separator, but they should be extended to an inspection of the 

 upper or neck bearing of the bowl, the lower bearings, the gear- 

 ing, if any, the advertised capacity and speed of the bowl, the 

 way in which the height of the bowl is adjusted, the cream 

 screw and its adjustment, the skimming tubes in the bowl, and 

 the means by which the power is applied to the bowl to re- 

 volve it. 



Method of Testing a Cream Separator 



289. Nearly all manufacturers are willing to have their 

 machines tested by the purchaser before buying it. Such a test 

 may include some or all of the following observations: 



1. Time required to take apart, clean and put together ready 

 for skimming. 



2. Time to get up to full speed. 



3. Turns of crank per minute (if hand machine). 



4. Noise of machine and space occupied. 



5. Weight and measure of the frame and bowl and its part. 



6. Weight of cream, Ibs., and of skim milk, Ibs., collected 

 from the machine in one-half minute, both to be sampled and 

 carefully tested when first the bowl is running at speed required 

 by the manufacturer; second, when running 10% under normal 

 speed; third, when temperature of milk is 75 degrees F. ; fourth, 

 when temperature of milk is 85 degrees ,F. 



290. From the weights of cream and skim milk collected 

 in one-half minute the capacity of the separator or the pounds 



