260 Milk and Its Products. 



To Change "Board of Health" Lactometer Degrees to 

 Equivalent Quevenne Degrees. 



Multiply the "Board of Health" reading by .29; e. g.: "Board 

 of Health " reading, 105 X -29 = 30.45 = 30-f Quevenne reading. 



To Change Quevenne Lactometer Degrees to Equivalent 

 "Board of Health" Degrees. 



Divide the observed Quevenne reading by .29; e. g.; Quevenne 

 reading, 34 -=- .29 = 117. -[- ordinary or "Board of Health" reading. 



Temperature Correction for Lactometer. 



For Quevenne lactometer, .1 lactometer degree for each degree of 

 temperature F. 



For ordinary or "Board of Health" lactometer, 1 lactometer degree 

 for each 3 degrees of temperature F. 



To be added if the temperature is too high, or subtracted if it is 

 too low. 



To be used only when the temperature variation is less than 10 

 degrees from the standard of the lactometer. 



To Estimate Solids Not Fat, and Total Solids, from the 

 Specific Gravity and Per Cent of Fat. 



The following formulae may be used : 

 L + .7 f 



Babcock (1) S = 



3.8 



Babcock (2) S = ^ -f .2 f 

 4 



Richmond (3) T = ^^ -\- ^1 + .14 

 4 5 



In the above L = corrected Quevenne lactometer reading,, f = per 

 cent of fat, S = solids not f at ; T = total solids ; solids not fat -(- 

 fat = total solids. 



To apply the above formulae, if the percentage of fat is 4.2 and 

 the lactometer reading at 60° F. is 32, then 



n\ S- L4- -7 f ^_ 32 -f .7 (4.2) 



.7 of 4.2 = 2.94 4- 32 = 34.94 h- 3.8 = 9.19 = solids not fat. 

 9.19 -f 4.2 = 13.39 = total solids. 



