OLEO-REFRACTO METER. 



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there will be no refraction. If, however, the prism contains a 

 different liquid, the refraction will be indicated (in arbitrary 

 degrees) by the position of the junction between the light and 

 dark halves of the field on the scale. 



A standard oil (huile type) * is supplied with the instrument, 

 and the scale is so adjusted as to read zero when this is placed 



Fig. 37. Oleo-refractometer. 



in the instrument. The oil or fat to be tested is placed in the 

 hollow prism and the position of the dividing line read off on 

 the scale. The temperature is kept constant by means of a 

 jacket, and is usually 45 C. 



* This is usually translated as " typical oil " ; the word " standard " is 

 more nearly equivalent to the French " type," than is " typical." 



