Milkotester Master Pro Operating Instructions Manual page 51

The Health authorities establish the basic freezing point or agriculture
departments in some regions, sometimes by universities, separate dairy
producers, or their associations. Frequently, tolerances have been
established on top of a basic freezing point to allow some variations in the
milk as well as device or operator variations.
Without mentioning the basic freezing point, the Association of
Official Analytical Chemists now recommends an upper limit freezing point
at -0,525°C (2,326 standard deviations above the most recently
determined North American average of –0,5404°C), below which there
will be at 95% confidence that will show 99% of all freezing point
determinations on dewatered milk:
"if the freezing point is –0,525°C or below, milk may be presumed to be
free of water or may be confirmed as water free by tests, specified below.
If the freezing point is above –0,525°C, milk will be designated as
"presumptive added water" and will be confirmed as added water or added
water free by tests specified below. Evaluate extreme daily fluctuations in
the freezing point of herd, pooled herd, or processed milk for presence of
added water".
"Presumed added water", as described above, must be "confirmed" by
means of tests on authentic milk samples obtained as specified in the
АОАС METHODS.
After determination the freezing point of your sample via the milk
analyzer, the added water is calculated using the following formula:
AddedWater
Where:
FrPointBase is the basic freezing point
FrPointCalc is measured freezing point
−
FrPo int FrPo int
=
Base
FrPo int
Base
51
Ultrasonic milk analyzers
∗
Calc
100 [%]
Operating Instructions Master Pro
Milkotester Ltd