ANNEXMETHODS OF SAMPLING RELATED TO THE CONTROL OF CHEMICAL ANALYSIS OF CERTAIN PARTLY OR WHOLLY DEHYDRATED PRESERVED MILK PRODUCTS
IV.BORERS FOR THE SAMPLING OF POWEDERED PRESERVED MILK IN BULK
1.Types of borer
Type A: long
Type B: short
(see Fig. 5).
2.Materials
Blade and stem shall be made of polished metal, preferably stainless steel.
The grip of the long trype should preferably be made of stainless steel.
The short type borer shall have a detachable grip of wood or plastic, fitted with a bayonet catch in the blade.
3.Construction
3.1.
Shape, material and finish shall be such as to permit the borer to be easily cleaned.
3.2.
The protruding edge of the blade of type A shall be sufficiently sharp to serve as a scraper.
3.3.
The point of the blade shall be sufficiently sharp to facilitate sampling.
4.Principal dimensions
The borers shall conform to the dimensions (subject to a tolerance of 10 %) given in the table hereafter:
(Dimensions in mm) | ||
Type A long | Type B short | |
|---|---|---|
Length of blade | 800 | 400 |
Thickness of metal of blade | 1 to 2 | 1 to 2 |
Inner diameter of blade at point | 18 | 32 |
Inner diameter of blade at grip or stem | 22 | 28 |
Slit width at point | 4 | 20 |
Slit width at grip or stem | 14 | 14 |
5.Note on use of borers
5.1.
With less free-flowing powders, the borers can be inserted vertically. Type A borers are then filled completely by turning and can be withdrawn vertically. Type B borers are already filled completely during insertion but must be withdrawn in an oblique position to prevent losses from the lower end.
5.2.
In the case of free-flowing powder, the container shall be inclined, the borers inserted nearly horizontally with the slit downwards and withdrawn with the slit upwards.