Milkotester Master Pro Operating Instructions Manual page 20

B/ Gerber method
The proteins in the milk and dairy products are dissolved with
sulphuric acid with definite concentration in butyrometer and the fat is
separated under the influence of amyl alcohol, heating and centrifuging in
a form of dense, transparent layer. The volume of this layer is measured in
the divided part of the butyrometer.
This is quick, easy method with sufficient accuracy. We recommend
it for usage. For more detailed description see Appendix Methods.
5.1.2.1.2. Milk density determination
Density = Mass/Volume
Generally, the density for cow milk at 20°C is about 1.030 kg/l
Density results appear on display (minus 1000). So, when the density is
1.030 kg/l, on the milk analyzer display is 30.
This applies on the COW, SHEEP, BUFFALO, GOAT and UHT milk.
The formula is different for CREAM. The results appear on display (minus
980), so when the density is 32 on display, actually is 1.012 kg/l
А/ With pycnometer and Mor-Vestval scales
This is the most exact method for determination of milk and its
derivatives' density.
B/ With aerometer (lacto-density-meter)
Compared with the above method this is quick and easy readable
with satisfactory accuracy. We recommend it. For more detailed
description see Appendix Methods.
During the lactation period and under the influence of different zoo
engineering factors the density of the different milk kinds varies in the
following bounds:
Milk kind
Cow
Buffalo
Goat
Sheep
Minimum
1,027
1,026
1,027
1,031
20
Ultrasonic milk analyzers
Maximum
1,033
1,032
1,033
1,040
Operating Instructions Master Pro
Milkotester Ltd
Average
1,030
1,029
1,030
1,034