TESTING FOR BUTTERFAT 621 



SPECIFICATIONS AND TOLERANCES FOR STANDARD 

 CREAM TEST BALANCES 



UNITED STATES BUREAU OF STANDARDS 1 



Definition. A cream-test or butterfat-test scale is a scale 

 especially designed and adapted for determining the fat content 

 of cream or butter. 



Specifications. 1. All scales shall be provided with a gradu- 

 ated scale or arc divided into at least 10 equal spaces, over which the 

 indicator shall play. 



2. The clear interval between the graduations on the graduated 

 scale or arc shall not be less than 0.05 inch. 



3. The indicator shall be of such length as to reach to the gradu- 

 ated divisions and shall terminate in a fine point to enable the read- 

 ings to be made with precision. 



4. All scales whose weight indications are changed by an 

 amount greater than one-half the tolerance allowed, when set in any 

 position on a surface making an angle of 5 per cent or approximately 

 j degrees with the horizontal, shall be equipped with leveling screws 

 and with a device which will indicate when the scale is level. The 

 scale shall be rebalanced at zero each time its position is altered dur- 

 ing this test. 



5. All scales shall be so constructed and adjusted that when 

 the pans are released or disturbed, the pointer will return to its orig- 

 inal position of equilibrium. 



Sensibility Reciprocal. The maximum sensibility reciprocal 

 allowable for these scales shall not exceed one-half grain, or approxi- 

 mately 30 milligrams, when the maximum load is placed upon the 

 scale. 



(The term "sensibility reciprocal" means the weight required to 

 move the position of equilibrium of the beam, pan, pointer, or other 

 indicating device of the scale a definite amount. In scales provided 

 with a pointer and a graduated scale or arc, such as the above, the 

 sensibility reciprocal is the weight required to cause a change in the 

 position of rest of the pointer equal to one division on the graduated 

 scale or arc.) 



Tolerances. The tolerance to be allowed in excess or de- 

 ficiency on all cream-test and butterfat-test scales shall not be 



1 United States Bureau of Standards, Tolerances and Specifications for 

 Weights and Measures, Proceedings of Tenth Annual Conference on the 

 Weights and Measures of the United States, May 25-28, 1915. 



