BOTSWANA AGRICULTURAL MARKETING BOARD: SUBSIDIARY LEGISLATION
INDEX TO SUBSIDIARY LEGISLATION
Maize (Classification and Grading) Regulations
Sorghum (Classification and Grading) Regulations
Sunflower Seed (Classification and Grading) Regulations
MAIZE (CLASSIFICATION AND GRADING) REGULATIONS
(under section 19)
(18th June, 1976)
ARRANGEMENT OF REGULATIONS
REGULATION
PART I
Preliminary
1. Citation
2. Interpretation
3. Scope of Regulations
PART II
Classification and Grading
4. Classes
5. Grades
6. Deviations
7. Weevily maize
PART III
Packing
8. Packing of maize
PART IV
Calculation and Testing Methods
9. Sampling and determination of defects
10. Determination of weight of samples
11. Determination of net weight of maize
12. Determination of moisture content
S.I. 80, 1976.
PART I
Preliminary (regs 1-3)
These Regulations may be cited as the Maize (Classification and Grading) Regulations.
In these Regulations, unless the context otherwise requires—
“10-mesh handsieve” means a handsieve with a wire mesh surface of 300 mm to 310 mm by 300 mm to 310 mm which is made of light plated steel wire with a nominal diameter of 0,45 mm and with meshes of 2,09 mm by 2,09 mm;
“20-mesh handsieve” means a handsieve with a wire mesh surface of 300 mm to 310 mm by 300 mm to 310 mm which is made of light plated steel wire with a nominal diameter of 0,30 mm and with meshes of 0,97 mm by 0,97 mm;
“defective maize kernels” means maize kernels—
(a) which are wizened or obviously immature, maize kernels which have a distinctly chalky texture throughout or which are mouldy or discoloured, excluding normal browning by oxidation, discolouration limited to the connecting tip of the kernel and pinking;
(b) which are sprouted, including kernels of which the growing point (plumule) in the germ is visibly discoloured;
(c) with cavities in the germ or endosperm caused by insects or rodents;
(d) which are visibly contaminated by smut, soil, smoke or coal dust;
(e) pieces of maize kernels which pass through a screen with 6,35 mm round holes;
(f) which are otherwise clearly of inferior quality; and
(g) of cultivars other than Zea mays indentata or Zea mays indurata such as bread maize (flour-corn), popcorn, sweet corn and waxy maize;
“foreign matter” means any matter other than maize;
“maize” means the threshed seed of the plant Zea mays indentata or Zea mays indurata;
“maize kernels of another colour”, in relation to—
(a) white maize, means maize kernels of a colour other than white, excluding pinked maize kernels;
(b) yellow maize, means maize kernels of a colour other than yellow, excluding pinked maize kernels;
“pinked maize kernels”, in relation to—
(a) white maize, means maize kernels of which the endosperm is white and of which the pericarp or part thereof is of a red or pink colour;
(b) yellow maize, means maize kernels of which the endosperm is yellow and of which the entire surface of the pericarp is of a red colour;
“white maize” means the threshed white seed of the plant Zea mays indentata or Zea mays indurata;
“yellow maize” means the threshed yellow seed of the plant Zea mays indentata or Zea mays indurata.
These Regulations shall apply to maize which—
(a) is either bought or sold or bought and sold by the Board commencing with the 1974/75 crop, but shall not apply to any stocks of maize held by the Board from any earlier crop;
(b) is imported into or exported from Botswana by the Board, but shall not apply to any exports from Botswana for which the classification or grade of maize stipulated by the foreign buyer is different from those specified herein.
PART II
Classification and Grading (regs 4-7)
There shall be five classes of maize, namely—
(a) white dent, i.e. maize consisting of not less than 90 percent (by weight) maize of the white dent type, provided it complies at least with the requirements of the Grade WD3;
(b) white flint, i.e. maize (other than maize of the class white dent as described in paragraph (a)) consisting of not less than 95 percent (by weight) white maize of any type, provided it complies at least with the requirements of the Grade WF2;
(c) yellow flint, i.e. maize consisting of not less than 90 percent (by weight) maize of the yellow flint type, provided it complies at least with the requirements of the Grade YF1;
(d) yellow flint-and-dent, i.e. maize (other than maize of the class yellow flint as described in paragraph (c)) consisting of not less than 95 percent (by weight) yellow maize of any type, provided it complies at least with the requirements of the Grade YM3;
(e) sample-grade, i.e. maize other than maize of any of the above-mentioned classes.
(1) The grades for the different classes of maize (excluding the class sample-grade) shall be as follows—
|
Class of maize |
Grades |
|
White dent ……………………………………… |
WD1, WD2 and WD3 |
|
White dent ……………………………………… |
WD1, WD2 and WD3 |
|
White flint ……………………………………….. |
WF1 and WF2 |
|
Yellow flint ………………………………………. |
YF1 |
|
Yellow flint-and-dent …………………………. |
YM1, YM2 and YM3. |
(2) Subject to the allowable deviations prescribed in regulation 6, maize of any of the grades referred to in subregulation (1) shall comply with the requirements prescribed in subregulation (3).
(3) The maize shall be—
(a) free from a musty, sour or other objectionable odour;
(b) free from foreign matter;
(c) of a standard which makes it suitable for the manufacture of maize products for human consumption;
(d) free from defective maize kernels:
Provided that maize kernels which are chipped or cracked, or pieces of maize kernels which are in a sound condition shall not be regarded as defective maize kernels except in the case of such maize kernels and pieces of maize kernels which will pass through a 6,35 mm round-hole screen;
(e) free from maize kernels of another colour and pinked maize kernels; and
(f) free of any moisture content in excess of 12 percent (by weight).
The maximum deviation from the requirements prescribed under regulation 5 which may be allowed in respect of any of the said grades shall be as follows—
|
|
Maximum percentage (by weight) of deviation allowed |
||||||||
|
|
White dent |
|
White flint |
Yellow flint |
Yellow flint and dent |
||||
|
|
WD1 |
WD2 |
WD3 |
WF1 |
WF2 |
YF1 |
YM1 |
YM2 |
YM3 |
|
(i) Defective maize kernels |
7 |
13 |
20 |
10 |
25 |
9 |
9 |
20 |
30 |
|
(ii) Maize kernels of another colour |
2 |
3 |
5 |
2 |
5 |
2 |
2 |
5 |
5 |
|
(iii) Foreign matter (excluding stones, pieces of coal or glass and manure) |
0,3 |
0,5 |
0,75 |
0,3 |
0,75 |
0,3 |
0,3 |
0,5 |
0,75 |
|
(iv) Defective maize kernels, maize kernels of another colour, and foreign matter collectively, provided such deviations are individual within the limits specified above |
7 |
13 |
20 |
10 |
25 |
9 |
9 |
20 |
30 |
|
(v) Pinked maize kernels |
12 |
12 |
12 |
12 |
12 |
7 |
7 |
7 |
7 |
|
(vi) Moisture |
2 |
2 |
2 |
2 |
2 |
2 |
2 |
2 |
2 |
The designations of the respective classes and grades of maize referred to in regulations 4 and 5 shall, notwithstanding anything to the contrary, include the words “weevily maize” in the case of maize infested with live weevils or other live insects injurious to stored grain irrespective of whether such insects are present in the maize or on the containers thereof.
PART III
Packing (reg 8)
(1) Maize shall either be bought or sold or bought and sold by the Board either in bulk or in grain bags.
(2) Grain bags in which maize is either bought or sold or bought and sold shall be new or good second-hand grain bags which—
(a) shall be manufactured from jute or phormium or jute and phormium;
(b) shall have a superficial measurement of not less than 7 484 cm2 and not more than 8 065 cm2 and which have been woven with porter and shot (warp and weft threads) of not less than-
(i) in the case of a jute bag and a jute-and-phormium bag, 32 warp and 32 weft threads per 100 mm;
(ii) in the case of a phormium bag, 36 warp and 40 weft threads per 100 mm; and
(iii) in the case of a B-Twill bag, 24 warp and 32 weft threads;
(c) are strong enough for the conveyance of 100 kg net maize and are not so weathered or worn that they will break during normal handling, or, when empty, will tear if one end is held down with the flat heel and the other end is pulled by hand;
(d) be clean and not stained by any colouring substance or impregnated by any liquid capable of imparting stains, excluding trade marks or normal discolouration due to exposure to the sun;
(e) be free from holes but may be darned with twine of which the tensile strength shall be not less than 40 newtons, or patched where necessary:
Provided that—
(i) none of the darns shall exceed 26 cm2 and that such darns shall overlap the small holes on all sides by at least 13 mm;
(ii) the darns shall be cross-stitched by hand with jute twine or machine-darned in such a manner that the darns correspond in closeness to the weave of the bag and that the material of the bag is not pulled together, thereby causing the snapping or displacement of the strands of the bag or the darns when the bag is filled with maize;
(iii) except for not more than two patches (one on each side) of not more than 38 mm by 254 mm each allowed at the mouth of the bag to cover cuts and affixed as indicated in paragraph (v), none of the other patches shall exceed 39 cm2;
(iv) patches, whether stitched or affixed with an adhesive, shall not overlap;
(v) patches shall be properly hand-sewn to the bags with jute twine or properly machine-darned over the entire surface of the patch with twine, the tensile strength of which shall be not less than 40 newtons;
(vi) patches affixed with an adhesive shall be properly affixed and will not be allowed to be closer than 150 mm from the mouth of the bag; and
(vii) bags of which the mouth sections have been replaced shall not be acceptable.
PART IV
Calculation and Testing Methods (regs 9-12)
9. Sampling and determination of defects
In the determination of the grade of maize, the following methods shall be followed—
(a) Sampling.
Samples of maize to be graded shall be taken in such manner as to be representative of such maize—
(i) in the case of maize in bags, this shall consist of withdrawing, by means of a hollow spear-probe, samples from not less than 10 percent of the bags in any one lot, chosen at random, except that no total sample in respect of any one lot shall weigh less than 500 grammes;
(ii) in the case of static bulk maize, this shall consist of withdrawing, by means of a bulk grain-probe, samples from various points and from various depths, chosen at random, of the bulk;
(iii) in the case of moving bulk maize, this shall consist of taking samples from the moving stream of grain at regular intervals whilst the grain is in motion;
(iv) samples drawn in the manner prescribed in subparagraphs (i), (ii) and (iii) shall be thoroughly mixed either by hand or by Boerner Sampler to ensure an homogeneous sample before being submitted to analysis for grading.
(b) Determination of percentage (weight by weight) of defective maize kernels-
The percentage (weight by weight) of defective maize kernels shall be determined by screening a sample of 100 grammes (taken in the manner prescribed in paragraph (a)) through a screen with 6,35 mm round holes and hand-picking the remaining portion and by calculating the weight of the defective maize kernels thus hand-picked together with that of the pieces of maize kernels and maize kernels which passed through the screen as a percentage of the total weight of the 100 grammes samples.
(c) Determination of percentage (weight by weight) maize kernels of another colour-
The percentage (weight by weight) maize kernels of another colour shall be determined by separating by hand from a sample of 200 grammes (taken in the manner prescribed in paragraph (a)) the maize kernels of another colour and by calculating the weight of such maize kernels of another colour as a percentage of the total weight of the sample.
(d) Determination of percentage (weight by weight) of foreign matter-
The percentage (weight by weight) of foreign matter shall be determined by separating by hand from a sample of at least 200 grammes (taken in the manner prescribed in paragraph (a)) the foreign matter and by calculating the weight of such foreign matter as a percentage of the total weight of such foreign matter as a percentage of the total weight of the sample.
(e) Determination of percentage (weight by weight) of pinked maize kernels-
The percentage (weight by weight) of pinked maize kernels shall be determined by separating by hand from a sample of 100 grammes (taken in the manner prescribed in paragraph (a)) the pinked maize kernels and by calculating the weight of such pink maize kernels as a percentage of the total weight of the sample.
10. Determination of weight of samples
The scale used for the determination of the weight of a sample of maize or other coloured kernels or of pinked maize kernels or of defective maize kernels or of foreign matter in the sample shall be such that the relevant weight can be accurately determined to within 0,5 grammes.
11. Determination of net weight of maize
The net weight of maize in grain bags shall be calculated by subtracting from the gross weight of the maize 1,1 kg per each bag plus the weight represented by moisture in excess of 12 percent (weight by weight) in the maize (if the moisture content of the maize at the time of sale exceeds 12 percent (weight by weight)).
12. Determination of moisture content
The moisture content of a quantity of maize shall be determined by the Marconi electrical resistance method, as follows—
The apparatus for moisture determination shall consist of the Marconi Moisture Meter Model TF 933 or TF 933A or TF 933B by which moisture content in maize is determined through electrical resistance. The apparatus shall be placed away from draughts and the direct rays of the sun in a permanent position in a room or store where all moisture determinations shall be carried out. A Celsius thermometer shall be attached to the outside of the instrument case of the apparatus so that the thermometer bulk is fully exposed to the free air in the room or store.
A quantity of not less than 70 grammes and not more than 80 grammes of a representative sample of the maize to be tested for moisture (taken in the manner prescribed in regulation 9(a)) shall be ground in a hand grain mill or coffee mill which has been so adjusted that at least 90 percent (weight by weight) of the ground product will pass through a 10-mesh sieve and not more than 75 percent (weight by weight) thereof will pass through a 20-mesh sieve. (This result can generally be obtained by adjusting the grinding plates as tightly as possible and then loosening the latter about one-quarter turn.) The mill shall be operated at a uniform speed which allows the entire sample to be ground in a period of not less than 30 seconds and not more than 90 seconds. The ground sample shall immediately be transferred to a screw-up glass jar of between 300 ml and 400 ml capacity. After the jar has been properly closed by screwing the cap on tightly, the contents shall be thoroughly mixed by shaking the jar for at least 30 seconds. Immediately thereafter the test cell of the Marconi apparatus shall be filled approximately half full with the ground sample, and the metal plunger shall be placed in position on it. Care shall be taken to ensure that the surface of the sample is level in the cell and that the parts of the cell fit properly into one another. The cell shall be handled only by the outer insulating material surrounding it. Immediately thereafter the cell (with the metal plunger facing upwards) shall be fitted into the clamp which forms part of the Marconi apparatus and screwed tight until the two parts of the cylindrical spring housing mounted on the screw are flush. The clamp containing the cell shall have a proper electric contact with the main apparatus. The switch shall now be turned to the “zero” position, and the galvanometer pointer shall thereafter be adjusted by means of the “Setzero” knob above the dials until the pointer is exactly opposite the horizontal line. When setting to zero, the left-hand dial shall be at any one of the positions 1 to 5. The switch shall then be turned to the “Read” position and the dials immediately adjusted until the galvanometer pointer returns to the position of the horizontal line.
The dial reading shall now be taken and the temperature be read (to the nearest degree) from the thermometer attached to the main apparatus. Any gradual movement of the pointer, after having been correctly adjusted, shall be disregarded. Not more than one minute shall elapse between the placing of the samples in the cell and the taking of the final dial reading. Whenever possible, readings shall only be taken on the black or positive values on the dials. Dial reading shall be converted into percentages according to the following table—
|
Dial reading |
Percentage |
Dial reading |
Percentage |
|
0 |
8,6 |
26 |
13,1 |
|
1 |
8,8 |
27 |
13,4 |
|
2 |
8,9 |
28 |
13,6 |
|
3 |
9,0 |
29 |
13,8 |
|
4 |
9,2 |
30 |
14,0 |
|
5 |
9,3 |
31 |
14,2 |
|
6 |
9,5 |
32 |
14,5 |
|
7 |
9,6 |
33 |
14,7 |
|
8 |
9,8 |
34 |
14,9 |
|
9 |
10,0 |
35 |
15,1 |
|
10 |
10,1 |
36 |
15,4 |
|
11 |
10,3 |
37 |
15,7 |
|
12 |
10,5 |
38 |
16,0 |
|
13 |
10,6 |
39 |
16,3 |
|
14 |
10,8 |
40 |
16,6 |
|
15 |
11,0 |
41 |
16,8 |
|
16 |
11,2 |
42 |
17,1 |
|
17 |
11,3 |
43 |
17,4 |
|
18 |
11,5 |
44 |
17,7 |
|
19 |
11,7 |
45 |
18,0 |
|
20 |
12,0 |
46 |
18,3 |
|
21 |
12,2 |
47 |
18,6 |
|
22 |
12,3 |
48 |
19,0 |
|
23 |
12,5 |
49 |
19,4 |
|
24 |
12,7 |
50 |
19,9 |
|
25 |
12,9 |
51 |
20,3 |
The result thus obtained shall be corrected for temperature by increasing it by 0,1 percent for each degree Celsius that the temperature reading is below 20℃C and by decreasing it by 0,1 percent for each degree Celsius that the temperature is above 20℃C. The test shall be carried out in duplicate without interruption with separate quantities of the original ground sample, and if the two results thus obtained do not differ by more than 0,3 the average of the two results shall be taken as the percentage moisture content of the maize from which the sample was taken. If the results of the two determinations differ by more than 0,3 the determination shall be repeated with further quantities of the original ground sample until two results are obtained which do not differ by more than 0,3. Care shall be taken that the mill used for the grinding of the sample, the jar used for mixing the sample and the pressure cell of the apparatus are clean and dry before each determination is commenced. The moisture meter shall be in equilibrium with the temperature of the ambient air in order to obviate the generation of thermo-electric currents in the instrument which may cause errors in the dial reading. For this reason it is imperative that the moisture meter shall remain in one position for an appreciable time before a moisture test is carried out. If for some special reason the moisture meter has to be moved to another position or some other locality, it should be left undisturbed for at least one hour in the new position to allow the instrument to come into thermal equilibrium with the ambient air before a moisture test is carried out. If it is not possible to affix the thermometer to the case of the instrument, it should be placed in a convenient horizontal position on top of the apparatus at least 15 minutes before a moisture test is started. In those cases, too, where the thermometer can be affixed to the apparatus but does not remain in that position permanently, it should be placed in that position at least 15 minutes before the commencement of a moisture test.
When a moisture determination is made by means of this method, it shall be ensured that the apparatus is in good working order by short circuiting the two topmost sockets on the main apparatus with a short piece of wire and turning the switch to “zero” and adjusting the galvanometer pointer until it is opposite the horizontal line. After the switch has been turned to “Read”, the reading on the dials, taken in the manner described above, should be approximately 60.
The wire shall then be removed. Thereafter the clamp shall be connected electrically with the main apparatus, as described above, the switch turned to “zero”, the galvanometer pointer adjusted to the position opposite the horizontal line and the base of the test cell kept in its normal position in the clamp. A piece of metal wire or silver paper (tin foil) shall be placed across the exposed electrodes (the metal parts) of the test cell and pressed down so as to cause a short circuit. After the switch has been turned to “Read”, the dial reading, taken in the manner described above, should be approximately 60. Thereafter the base and the insulator ring of the test cell shall be placed in the clamp and screwed down without the plunger until they just fit tightly, the switch turned to “zero” and the galvanometer pointer adjusted to the position opposite the horizontal line. After the switch has been turned to “Read” the reading on the dials in this instance will be nil or lower, but if the reading is higher than nil the base of the test cell may be exposed to sunlight or reasonably warm air for a few minutes and the test repeated.
SORGHUM (CLASSIFICATION AND GRADING) REGULATIONS
(under section 19)
(18th June, 1976)
ARRANGEMENT OF REGULATIONS
REGULATION
PART I
Preliminary
1. Citation
2. Interpretation
3. Scope of Regulations
PART II
Classification and Grading
4. Classes
5. Grades
6. Deviations
7. Sample grade sorghum
8. Weevily sorghum
PART III
Packing
9. Packing of sorghum
PART IV
Calculation and Testing Methods
10. Sampling and determination of defects
11. Anthocyanic blotches
12. Determination of weights
13. Determination of moisture content
S.I. 81, 1976.
PART I
Preliminary (regs 1-3)
These Regulations may be cited as the Sorghum (Classification and Grading) Regulations.
In these Regulations, unless the context otherwise requires—
“bulk probe” means a double tube probe with multiple openings on the same side of both tubes;
“defective sorghum” means—
(a) pieces of grain sorghum; or
(b) grain sorghum—
(i) which is broken, rotten, mouldy, smutty, or otherwise diseased;
(ii) of which the embryo skin is cracked;
(iii) which has a green colour or shows other signs of immaturity;
(iv) which has been damaged by insects, heat or any other means, but does not include weather-stained sorghum;
(v) which passes through a 1,8 mm slotted sieve;
“foreign matter” means all material other than sorghum such as sticks, stones, clods, dung, chaff, other portions of the sorghum plant, other plants and seed kernels of other plants;
“grain sorghum” means the threshed seed of the plant Sorghum vulgare excluding broom corn, hay sorghums and sweet sorghums;
“1,8 mm slotted sieve” means a sieve made of metal of 1 mm thickness which complies with the following specifications—
(a) the inner measurements of the sieve shall be 200-210 mm in length and 200-210 mm in width and at least 50 mm deep;
(b) the sieve shall have 8 parallel rows of slotted perforations measuring 20 mm in length and 1,8 mm width;
(c) the slotted perforations in the different rows shall run in columnar formation and not in chess board formation;
(d) the ribs between the slotted perforations in the same row shall be 2,4 mm wide; and
(e) the sieve shall fit into a solid bottom pan;
“10-mesh handsieve” means a handsieve with a wire mesh surface of 300-310 mm by 300-310 mm which is made of light plated steel wire with a nominal diameter of 0,45 mm and with meshes of 2,09 mm by 2,09 mm;
“20-mesh handsieve” means a handsieve with a wire mesh surface of 300-310 mm by 300-310 mm which is made of light plated steel wire with a nominal diameter of 0,30 mm and with meshes of 0,97 mm by 0,97 mm;
“red”, in relation to grain sorghum, means that the colour of the pericarp ranges from yellow through pink, red to reddish brown, irrespective of any purplish anthocyanic blotches in or on the pericarp;
“sorghum of another colour”, in relation to—
(a) white sorghum, means sorghum of a colour other than white, irrespective of purplish anthocyanic blotches in or on the pericarp, or which has a dark nucellar layer;
(b) red sorghum, means sorghum of a colour other than one ranging from yellow through pink, red and reddish brown, irrespective of purplish anthocyanic blotches in or on the pericarp, or which has a dark nucellar layer;
“unthreshed sorghum” means sorghum or pieces of sorghum still enclosed in glumes;
“weather-stained sorghum” means sorghum of which more than one-third of the surface is distinctly discoloured by the weather:
Provided that purplish anthocyanic blotches in or on the pericarp shall not be regarded as discolouration by the weather;
“weevily sorghum” means sorghum infested with live weevils or other live insects injurious to stored grain, irrespective of whether such insects are present in the sorghum or on the containers thereof;
“white”, in relation to grain sorghum, means that the colour of the pericarp does not display any of the shades of colour ranging from yellow through pink, red to reddish brown, irrespective of any purplish anthocyanic blotches in or on the pericarp.
These Regulations shall apply to grain sorghum which—
(a) is either bought or sold or bought and sold by the Board commencing with the 1974/75 crop, but shall not apply to any stocks of sorghum held by the Board from any earlier crop;
(b) is imported into or exported from Botswana by the Board, but shall not apply to any exports from Botswana for which the classification or grade of sorghum stipulated by the foreign buyers is different from those specified herein.
PART II
Classification and Grading (regs 4-8)
There shall be four classes of grain sorghum, namely—
(a) white sorghum, i.e. sorghum consisting of not less than 90 percent (weight by weight) white sorghum, irrespective of any purplish anthocyanic blotches in or on the pericarp, and which does not have a dark nucellar layer provided that it complies at least with the Grade SW2;
(b) red sorghum, i.e. sorghum consisting of not less than 90 percent (weight by weight) sorghum of any colour ranging through yellow, pink, red and reddish brown, irrespective of any purplish anthocyanic blotches in or on the pericarp, and which does not have a dark nucellar layer, provided it complies at least with the Grade SR2;
(c) mixed sorghum, i.e. sorghum consisting of not less than 90 percent (weight by weight) sorghum of any colour and which does have a dark nucellar layer, provided it complies at least with the Grade SM3; and
(d) sample-grade, i.e. sorghum other than sorghum of any of the above-mentioned classes.
(1) The grades for the different classes of sorghum (excluding the class sample-grade) shall be as follows—
|
Class of sorghum |
Grades |
|
White sorghum ……………………. |
SW1 and SW2 |
|
Red sorghum ……………………… |
SR1 and SR2 |
|
Mixed sorghum ……………………. |
SM1, SM2 and SM3. |
(2) Subject to the allowable deviations prescribed in regulation 6, sorghum of any of the grades referred to in subregulation (1) shall comply with the requirements prescribed in subregulation (3).
(3) The sorghum shall—
(a) be free from any musty, sour or other objectionable odour;
(b) be free from foreign matter;
(c) be of a standard which makes it suitable for the manufacture of sorghum products for human consumption;
(d) be of the colour of the respective class;
(e) not contain weather-stained sorghum;
(f) not contain sorghum of another class;
(g) be free from defective sorghum;
(h) be free from unthreshed sorghum;
(i) not be distinctly blackened by smut or not contain 10 or more smut balls or parts of smut balls which are collectively equivalent to 10 or more smut balls per 100 grammes of sorghum;
(j) be free from live weevils or other live insects injurious to stored grain, irrespective of whether such insects are in the sorghum or on the containers thereof;
(k) be free from poisonous chemical substances which may render such sorghum unsuitable for human or animal consumption; except if such sorghum is intended for seed purposes and the container in which the seed is packed is clearly marked to indicate that it contains sorghum which has been treated with a chemical substance; and
(l) have a moisture content not exceeding 12 percent (weight by weight).
The maximum deviation from the requirements prescribed under regulation 5 which may be allowed in respect of any of the said grades shall be as follows—
|
|
Maximum percentage (weight by weight) deviations allowed |
||||||
|
Grade |
Defective sorghum |
Unthreshed sorghum |
Sorghum of another colour |
Sorghum of other classes |
Foreign matter |
Weather Stained sorghum |
Moisture |
|
SW1 |
5,0 |
4,0 |
4,0 |
4,0 |
1,5 |
50 |
2,0 |
|
SW2 |
10,0 |
8,0 |
8,0 |
8,0 |
2,0 |
50 |
2,0 |
|
SR1 |
5,0 |
4,0 |
4,0 |
4,0 |
1,5 |
50 |
2,0 |
|
SR2 |
10,0 |
8,0 |
8,0 |
8,0 |
2,0 |
50 |
2,0 |
|
SM1 |
5,0 |
8,0 |
+ |
+ |
1,5 |
50 |
2,0 |
|
SM2 |
10,0 |
12,0 |
+ |
+ |
2,0 |
50 |
2,0 |
|
SM3 |
20,0 |
20,0 |
+ |
+ |
3,0 |
50 |
2,0 |
+Denotes no maximum.
Grain sorghum which does not comply with the requirements of regulations 5 and 6 or which contains Datura spp. seed shall be sample grade sorghum.
The designations of the respective classes and grades of sorghum referred to in regulations 4 and 5 shall, notwithstanding anything to the contrary, include the words “weevily sorghum” in the case of sorghum infested with live weevils or other live insects injurious to stored grain, irrespective of whether such live insects are present in the sorghum or on the containers thereof, provided that the word “weevily” shall be added to and made part of the class designation.
PART III
Packing (reg 9)
(1) Sorghum shall either be bought or sold or bought and sold by the Board either in bulk or in grain bags.
(2) Grain bags in which sorghum is either bought or sold or bought and sold shall be new or good second-hand grain bags which—
(a) are manufactured from jute or phormium or jute and phormium;
(b) have a superficial measurement of not less than 7484 cm2 and not more than 8065 cm2 and which have been woven with porter and shot (warp and weft threads) of not less than-
(i) in the case of jute bags and jute-and-phormium bags, 32 warp and 32 weft threads per 100 mm;
(ii) in the case of phormium bags, 36 warp and 40 weft threads per 100 mm;
(iii) in the case of B-Twill bags, 24 warp and 32 weft threads per 100 mm;
(c) are strong enough for the conveyance of 100 kg net sorghum and are not so weathered or worn that they will break during normal handling, or, when empty, will tear if one end is held down with the flat heel and the other end is pulled by hand;
(d) be clean and not stained by any colouring substance or impregnated by any liquid capable of imparting stains, excluding trade marks or normal discolouration due to exposure to the sun;
(e) be free from holes but may be darned with twine of which the tensile strength shall be not less than 40 newtons or patched where necessary:
Provided that—
(i) none of the darns shall exceed 26 cm2 and that such darns shall overlap the small holes on all sides by at least 13 mm;
(ii) the darns shall be cross-stitched by hand with jute twine or machine-darned in such a manner that the darns correspond in closeness to the weave of the bag and that the material of the bag is not pulled together, thereby causing the snapping or displacement of the strands of the bag or the darns when the bag is filled with sorghum;
(iii) except for not more than two patches (one on each side) of not more than 38 mm by 254 mm each allowed at the mouth of the bag to cover cuts and affixed as indicated in paragraph (v), none of the other patches shall exceed 39 cm2;
(iv) patches, whether stitched or affixed with an adhesive, shall not overlap;
(v) patches shall be properly hand-sewn to the bags with jute twine or properly machine-darned over the entire surface of the patch with twine, the tensile strength of which shall be not less than 40 newtons;
(vi) patches affixed with an adhesive shall be properly affixed and will not be allowed to be closer than 150 mm from the mouth of the bag; and
(vii) bags of which the mouth sections have been replaced shall not be acceptable.
PART IV
Calculation and Testing Methods (regs 10-13)
10. Sampling and determination of defects
In the determination of the grade of sorghum the following methods shall be employed—
(a) Sampling-
Samples of sorghum to be graded shall be taken in such manner as to be representative of such sorghum—
(i) in the case of sorghum in bags, this shall consist of withdrawing, by means of a hollow spear-probe (Trier), samples from not less than 10 percent of the bags in any one lot, chosen at random, except that no total sample in respect of any one lot shall weigh less than 500 grammes;
(ii) in the case of static bulk sorghum, this shall consist of withdrawing samples, by means of a bulk grain-probe from various points and from various depths, chosen at random, of the bulk;
(iii) in the case of moving bulk sorghum, this shall consist of taking samples from the moving stream of grain at regular intervals whilst the grain is in motion;
(iv) samples drawn in the manner prescribed in subparagraphs (i), (ii) and (iii) shall be thoroughly mixed either by hand or by Boerner Sample Divider to ensure an homogeneous sample before being submitted to analysis for grading.
(b) Determination of percentage (weight by weight) of defective sorghum-
The percentage (weight by weight) of defective sorghum shall be determined in the following manner:
Take a sample of 50 g of grain sorghum, obtained in the manner prescribed in paragraph (a), from which all foreign matter and unthreshed grain sorghum has been removed before determining the weight thereof. Place the grain sorghum in the 1,8 mm slotted sieve already placed in position on the pan. Screen the grain sorghum by moving the sieve to and fro, alternately away from and towards the operator, the direction of the motion being kept in line with the long axis of the slotted perforations of the sieve. Each to and fro movement constitutes one stroke and 30 such strokes complete the screening process. In each stroke the sieve is moved 230 mm to 305 mm away from and back to the operator, with the sieve resting on a table or other suitable smooth surface. The speed of the stroke movement shall be such that the prescribed 30 strokes are completed in 25 to 30 seconds. Hereafter the defective grain sorghum is separated by hand from the portion that remained in the sieve, including the grain sorghum and pieces of grain sorghum sticking in the slotted perforations of the sieve. The weight of the defective grain sorghum thus separated by hand together with the grain sorghum and pieces of grain sorghum that passed through the sieve is then calculated as a percentage of the total weight of the sample.
(c) Determination of unthreshed sorghum-
The percentage of unthreshed sorghum shall be determined by separating by hand from a sample of 50 g, obtained in the manner prescribed in paragraph (a), and from which all the foreign matter has been removed before weighing, all unthreshed sorghum, and by calculating the weight of the unthreshed sorghum thus obtained as a percentage of the total weight of the sample.
(d) Determination of sorghum of another colour-
The percentage of sorghum of another colour shall be determined by separating by hand from a sample of 50 g, obtained in the manner prescribed in paragraph (a), and from which all the foreign matter, unthreshed sorghum and defective sorghum have been removed before weighing, all sorghum of another colour and by calculating the weight of the sorghum of another colour thus obtained as a percentage of the total weight of the sample.
(e) Determination of sorghum of another class-
The percentage of sorghum of another class shall be determined by separating by hand from a sample of 50 g, obtained in the manner prescribed in paragraph (a), and from which all the foreign matter, unthreshed sorghum and defective sorghum have been removed before weighing, all the sorghum of other classes, and by calculating the weight of the sorghum of other classes thus obtained as a percentage of the total weight of the sample.
(f) Determination of foreign matter-
The percentage of foreign matter shall be determined by separating by hand from a sample of 100 g, obtained in the manner prescribed in paragraph (a), all foreign matter, and by calculating the weight of the foreign matter thus obtained as a percentage of the total weight of the sample.
(g) Determination of weather-stained sorghum-
The percentage of weather-stained sorghum shall be determined by separating by hand from a sample of 25 g, obtained in the manner prescribed in paragraph (a), and from which all the foreign matter, unthreshed sorghum and defective sorghum have been removed before weighing, all the weather-stained sorghum, and by calculating the weight of the weather-stained sorghum thus obtained as a percentage of the total weight of the sample.
The presence of purplish anthocyanic blotches in or on the pericarp shall be deemed not to affect the colour of sorghum which is otherwise white or red.
The scale used for the determination of any weight for the purpose of grading shall be such that the relevant weights can be accurately determined to within one-half of a gramme.
13. Determination of moisture content
The moisture content of a quantity of sorghum shall be determined by the Marconi electrical resistance method, as follows—
The apparatus for moisture determination shall consist of the Marconi Moisture Meter Model TF 933 or TF 933A or TF 933B by which moisture content in sorghum is determined through electrical resistance. The apparatus shall be placed away from draughts and the direct rays of the sun in a permanent position in a room or store where all moisture determinations shall be carried out. A Celsius thermometer shall be attached to the outside of the instrument case of the apparatus so that the thermometer bulb is fully exposed to the free air in the room or store.
A quantity of not less than 100 g and not more than 110 g of a representative sample (obtained in the manner prescribed in regulation 10(a)), of the sorghum to be tested for moisture content, shall be ground in a hand grain mill or coffee mill which has been so adjusted that at least 90 percent by weight of the milled product will pass through a 10-mesh hand sieve and not more than 75 percent by weight thereof will pass through a 20-mesh hand sieve. (This result can generally be obtained by adjusting the milling plates as tightly as possible by means of the adjusting screw and then by loosening the latter about one-quarter turn.) The mill shall be operated at a uniform speed which allows the entire sample being ground in a period of not less than 30 seconds and not more than 60 seconds. The milled sample shall immediately be placed in a screw cap glass jar of between 350 and 450 cubic centimetres capacity. After the jar has been closed by screwing the cap on tightly the contents shall be thoroughly mixed by shaking the jar for at least 30 seconds. Immediately thereafter the test cell of the Marconi apparatus shall be filled approximately half full with the milled sample and the metal plunger shall be placed into position on it. Care shall be taken to ensure that the surface of the sample is level in the cell and that the parts of the cell fit properly into one another. The cell shall be handled only by the outer insulating material surrounding it. Immediately thereafter the cell (with the metal plunger facing upwards) shall be fitted into the clamp which forms part of the Marconi apparatus and screwed tight until the two parts of the cylindrical spring housing mounted on the screw are flush. The clamp containing the cell shall have a proper electric contact with the main apparatus. The switch shall now be turned to the “zero” position and the galvanometer pointer shall thereafter be adjusted by means of the “Setzero” knob above the dials until the pointer is exactly opposite the horizontal line. When setting to zero, the left-hand dial shall be at any of the positions 1 to 5. The switch shall then be turned to the “Read” position and the dials immediately adjusted until the galvanometer pointer returns to the position of the horizontal line.
The dial reading shall now be taken and the temperature be read (to the nearest degree) from the thermometer attached to the main apparatus. Any eventual movement of the pointer, after having been correctly adjusted, shall be disregarded. Not more than one minute shall elapse between the placing of the samples in the cell and the taking of the final dial reading. Whenever possible readings shall only be taken on the black or positive values on the dials. Dial reading shall be converted into percentages according to the following table:
|
Dial reading |
Percentage |
Dial reading |
Percentage |
|
1 |
10,0 |
10 |
11,5 |
|
2 |
10,2 |
11 |
11,7 |
|
3 |
10,3 |
12 |
11,8 |
|
4 |
10,5 |
13 |
12,0 |
|
5 |
10,6 |
14 |
12,2 |
|
6 |
10,8 |
15 |
12,4 |
|
7 |
11,0 |
16 |
12,6 |
|
8 |
11,1 |
17 |
12,8 |
|
9 |
11,3 |
18 |
13,0 |
|
19 |
13,2 |
33 |
16,4 |
|
20 |
13,4 |
34 |
16,6 |
|
21 |
13,6 |
35 |
16,9 |
|
22 |
13,8 |
36 |
17,2 |
|
23 |
14,1 |
37 |
17,5 |
|
24 |
14,3 |
38 |
17,8 |
|
25 |
14,5 |
39 |
18,0 |
|
26 |
14,7 |
40 |
18,3 |
|
27 |
15,0 |
41 |
18,6 |
|
28 |
15,2 |
42 |
18,9 |
|
29 |
15,4 |
43 |
19,3 |
|
30 |
15,6 |
44 |
19,6 |
|
31 |
15,9 |
45 |
19,9 |
|
32 |
16,1 |
|
|
The result thus obtained shall be corrected for temperature by increasing it by 0,1 for each degree centigrade that the temperature reading is below 20℃C. and by decreasing it by 0,1 for each degree centigrade the temperature reading is above 20℃C.
The test shall be carried out in duplicate without interruption with separate quantities of the original milled sample and if the two results thus obtained do not differ by more than 0,3 the average of the two results shall be taken as the percentage moisture content of the sorghum from which the sample was taken. If the results of the two determinations differ by more than 0,3 the determination shall be repeated with further quantities of the original sample until two results are obtained which do not differ by more than 0,3.
Care shall be taken that the mill used for the grinding of the sample, the jar used for mixing the sample and the pressure cell of the apparatus are clean and dry before each determination is commenced.
When a moisture determination is made by means of this method it should be seen to that the apparatus is in good working order by short circuiting the two topmost sockets on the main apparatus with a short piece of wire, and turning the switch to “zero” and adjusting the galvanometer pointer until it is opposite the horizontal line. After the switch has been turned to “Read”, the reading on the dials, taken in the manner described above, should be approximately 60. The wire shall then be removed. Thereafter the clamp shall be connected electrically with the main apparatus as described above, the switch turned to “zero”, the galvanometer pointer adjusted to the position opposite the horizontal line and the base of the test cell kept in its normal position in the clamp. A piece of metal wire or silver paper (tin foil) shall be placed across the exposed electrodes (the metal parts) of the test cell and pressed down so as to cause a short circuit. After the switch has been turned to “Read”, the dial reading, taken in the manner described above, should be approximately 60. Thereafter the base and the insulator ring of the test cell shall be placed in the clamp and screwed down without the plunger until they just fit tightly, the switch turned to “zero” and the galvanometer pointer adjusted to the position opposite the horizontal line. After the switch has been turned to “Read”, the reading on the dials in this instance would be nil or lower but if the reading is higher than nil the base of the test cell may be exposed to sunlight or reasonably warm air for a few minutes after which the test shall be repeated.
SUNFLOWER SEED (CLASSIFICATION AND GRADING) REGULATIONS
(under section 19)
(18th February, 1977)
ARRANGEMENT OF REGULATIONS
REGULATION
1. Citation
2. Interpretation
3. Application
4. Classification and grading
5. Methods of sampling
6. Determination of percentage deviations
7. Determination of mass in kg per hl
8. Determination of moisture content of sunflower seed
S.I. 16, 1977.
These Regulations may be cited as the Sunflower Seed (Classification and Grading) Regulations.
In these Regulations, unless the context otherwise requires—
“castor seed” means the seed of the plant Ricinus spp;
“consignment”, in relation to sunflower seed, means a quantity of sunflower seed of the same class and grade delivered at any one time under cover of the same consignment note, delivery note or receipt note or from the same vehicle, or, if any quantity is divided into different cultivars, each quantity of the different cultivars;
“damaged sunflower seed” means—
(a) sunflower seed which has been damaged by insects;
(b) sunflower seed which is visibly infected with mould organisms or other fungi;
(c) sunflower seed or pieces of sunflower seed which have been distinctly discoloured by external heat or as a result of heating caused by internal fermentation in seed with a high moisture content;
(d) sunflower seed in which germination or sprouting has proceeded to such an extent that the hull thereof has been broken as a result of the development of the embryo; or
(e) sunflower seed of which the hulls have been broken or of which the hulls were opened in any way or which are partly decorticated;
“decorticated sunflower seed” means sunflower seed of which the hulls have been completely removed;
“foreign matter” means all material other than sunflower seed, including loose hulls of sunflower seed;
“insects” means the grain weevil (Sitophilus granarius Linn.), the rice weevil (Sitophilus oryzae Linn.) or the Angoumois grain moth (Sitotroga cerealella Oliv.);
“sunflower seed” means the fruit (Cypsela) of the plant Helianthus annuus.
These Regulations shall apply to sunflower seed sold by producers to or through the Board.
(1) For grading purposes sunflower seed is classified as follows—
(a) Class FH, which consists of the dull coloured, thin shelled, high-in-oil sunflower seed; and
(b) Class F, which consists of clearly striped and shiny black sunflower seed.
(2) Subject to the provisions of subregulation (4), the grades for sunflower seed shall be—
(a) FH1 and FH2 for Class FH; and
(b) F1 and F2 for Class F.
(3) Subject to the allowable deviations prescribed in subregulation (5), the specifications for the different grades of sunflower seed are as follows—
|
Quality factor |
Grade |
|||
|
FH1 |
FH2 |
F1 |
F2 |
|
|
(a) Damaged seeds …………………….. |
free |
free |
free |
free |
|
(b) Decorticated seeds ………………… |
free |
free |
free |
free |
|
(c) Foreign matter ………………………. |
free |
free |
free |
free |
|
(d) Mouldy, khaki bush or other objectionable odour ………………. |
free |
free |
free |
free |
|
(e) Maximum percentage moisture …. |
10 |
10 |
10 |
10 |
|
(f) Chemical substances which render the sunflower seed unsuitable for commercial purposes …………….. |
free |
free |
free |
free |
|
(g) Live insects …………………………… |
free |
free |
free |
free |
|
(h) Castor seed or other poisonous seeds ……………………………………. |
free |
free |
free |
free |
|
(i) The mass expressed as kg per hl (minimum) ………………………………. |
32,4 |
23,7 |
39,9 |
31,2 |
|
(j) Other classes of sunflower seed … |
free |
free |
* |
* |
|
* Denotes no specification. (4) Sunflower seed which does not comply with the specifications as prescribed in subregulation (3) shall be graded as Undergrade. |
||||
|
(5) Maximum percentage allowable deviations- |
||||
|
Quality factor |
Grade |
|||
|
FH1 |
FH2 |
F1 |
F2 |
|
|
(a) Damaged seeds ……………………… |
5 |
10 |
5 |
10 |
|
(b) Decorticated seeds …………………. |
5 |
10 |
5 |
10 |
|
(c) Foreign matter ……………………….. |
2 |
4 |
2 |
4 |
|
(d) Other classes ……………………….. |
15 |
20 |
* |
* |
*Denotes no specification.
For the purposes of these Regulations a random sample shall be drawn as follows—
(a) Out of bags: Samples for the testing of sunflower seed in bags shall be obtained by taking more or less equal quantities by hand or by means of a tubular probe or a grain probe from the bags to be graded. If the sample is taken by hand, not less than five percent of the bags taken at random from all the bags in a consignment shall be opened. If, however, the sample is taken by means of a tubular probe, at least five percent of the bags, taken at random, shall be removed from the consignment and a tubular probe inserted at one or more places at the mouth of the bag for the full length of the bag. When the sample is taken by means of a grain probe, each bag shall be probed at different levels and probing shall in all cases be done towards the centre of the bags. If the sunflower seed from all the bags in a consignment is found to be generally of the same quality, the samples from all the bags shall be thrown together and thoroughly mixed.
(b) When delivered in bulk: Samples shall be taken by means of a tubular probe. The tubular probe shall be inserted in at least four places for the whole depth of the bulk trailer or vehicle bed. Samples thus obtained shall be thrown together and thoroughly mixed.
(c) Deviation samples: If a grader should notice during the course of taking the random sample that the quantities of sunflower seed taken from any container are obviously inferior to that taken from the remainder of the containers, he shall take a separate random sample out of the containers containing such inferior sunflower seed. This sample shall be thoroughly mixed and shall for the purposes of these Regulations be regarded as a deviating sample. The bags from which the deviating samples have been drawn shall be placed aside and graded separately.
6. Determination of percentage deviations
(1) The percentage of damaged sunflower seed shall be determined as follows—
(a) measure out duplicate samples of 50 g each from either the random or deviating sample, as the case may be;
(b) sort out by hand or separate by means of sieves in such a manner that the damaged sunflower seed is retained;
(c) determine the mass of the damaged sunflower seed and express as a percentage of the mass of the sample; and
(d) if the difference between the percentages so determined in respect of the two samples does not exceed 0,5, the average of the two percentages so determined shall be taken. If the difference exceeds 0,5, the test shall be repeated.
(2) The percentage of decorticated sunflower seed shall be determined as follows—
(a) measure out duplicate samples of 50 g each from either the random or deviating sample, as the case may be;
(b) sort out by hand or separate by means of sieves in such a manner that the decorticated sunflower seed is retained;
(c) determine the mass of the decorticated sunflower seed and express as a percentage of the mass of the sample; and
(d) if the difference between the percentages so determined in respect of the two samples does not exceed 0,5, the average of the two percentages so determined shall be taken. If the difference exceeds 0,5, the test shall be repeated.
(3) The percentage of foreign matter shall be determined as follows—
(a) measure out duplicate samples of 50 g each from either the random or deviating sample, as the case may be;
(b) sort out by hand or by means of sieves in such a manner that the foreign matter is retained;
(c) determine the mass of the foreign matter and express as a percentage of the mass of the sample; and
(d) if the difference between the percentages so determined in respect of the two samples does not exceed 0,5, the average of the two percentages so determined shall be taken. If the difference exceeds 0,5, the test shall be repeated.
7. Determination of mass in kg per hl
(1) The mass in kg per hl shall be determined by the two-level funnel four-in-one scale method.
(2) A portion of the random or the deviating sample, as the case may be, is used for this purpose.
(3) The standard apparatus in this method is the following—
(a) a four-in-one scale;
(b) a bucket, internal height 124 mm, capacity 500 ml;
(c) a two-level funnel, top diameter 914 mm, diameter of shutterhole 285 mm;
(d) the funnel to be attached to a metal base by means of a cylindrical metal upright;
(e) the high level is used in the case of sunflower seed; and
(f) a wooden scraper, 10 mm thick, 40 mm wide and at least 100 mm long,
the edges of the scraper shall be well rounded, but not worn.
(4) Method of using apparatus:
The entire apparatus is placed or fastened on to a hard, smooth, level surface not subject to jarring or shaking. The funnel is filled with sunflower seed and scraped off level full. The bucket is then placed on the high level of the base of the stand. The funnel shutter is opened wide with a quick swing, the sunflower seed being allowed to fill the bucket and to overflow on all the sides. The funnel is then swung round away from the bucket without disturbing the bucket in any way. The surplus sunflower seed is then scraped from the bucket with the scraper which is held vertically. If the scraper has both a round and sharp edge, only the round edge may be used for scraping. In scraping the scraper is placed lightly but firmly on the rim of the bucket which is grasped gently but firmly with one hand and the surplus sunflower seed scraped off with one firm scrape straight across the rim of the bucket. The scraping should leave the bucket just level full of sunflower seed. The four-in-one-scale is placed on a firm base and balanced. The sunflower seed in the bucket is then poured into the pan of the four-in-one-scale and the mass determined in kg per hl. The determination shall be done twice with each sample and if the readings do not correspond, the test shall be repeated with a new sample.
8. Determination of moisture content of sunflower seed
(1) The moisture content shall be determined by the Marconi electrical resistance method.
(2) A random or deviating sample, as the case may be, of at least 30 g and not more than 40 g of sunflower seed from which the foreign matter has been removed, shall be taken.
(3) The standard apparatus is the following—
(a) a Marconi moisture meter Model TF933 or TF933A;
(b) a coffee mill or Alexander Work 466 mill or Philips electrical mill, or any other suitable mill; and
(c) a glass jar with a screw top and with a capacity of at least 350 ml and not exceeding 450 ml.
(4) Grinding of the sample: Grind the sample of sunflower seed, obtained as prescribed in subregulation (2), as follows—
(a) the mill shall be operated at a uniform speed;
(b) the milled portions shall be in a granulated form of uniform size;
(c) to obtain this degree of fineness the milling plates must be set as tightly as possible by means of the adjusting screw and then by loosening the latter by about one quarter turn;
(d) the milling process shall last one minute with 10 seconds pause after each 15 seconds; and
(e) the milled product shall immediately be transferred to the glass jar and after the lid has been screwed on properly the contents shall be thoroughly mixed by shaking the jar for at least 30 seconds.
(5) Method of determining the moisture content:
Immediately after the sample mentioned in subregulation (4) is ready, the test cell of the Marconi apparatus shall be filled approximately half full with the milled sample and the metal plunger shall be placed into position on it. Care shall be taken to ensure that the surface of the sample is level in the cell and that the parts of the cell fit properly into one another. The cell shall be handled only by the outer insulating material surrounding it. Immediately thereafter the cell (with the metal plunger facing upwards) shall be fitted into the clamp which forms part of the Marconi apparatus and screwed tight until the two parts of the cylindrical spring housing mounted on the screw are flush. The clamp containing the cell shall have proper electric contact with the main apparatus. The switch shall now be turned to the “zero” position and the galvanometer pointer shall thereafter be adjusted by means of the “set-zero” knob above the dials until the pointer is exactly opposite the horizontal line. When setting to “zero” the left-hand dial shall be at any one of the positions 1 to 5. The switch shall then be turned to the “Read” position and the dials immediately adjusted until the galvanometer pointer returns to the position of the horizontal line. The dial reading shall now be taken and the temperature be read to the nearest degree, from the thermometer attached to the main apparatus. Any gradual movement of the pointer, after having been correctly adjusted, shall be disregarded. Not more than one minute shall elapse between the placing of the samples into the cell and the taking of the final dial reading. Where possible, readings shall only be taken on the black or positive value of the dials. Dial readings shall be converted into percentages according to the following table—
|
Dial reading |
Percentage moisture |
Dial reading |
Percentage moisture |
|
0 |
4,46 |
28 |
8,33 |
|
1 |
4,56 |
29 |
8,52 |
|
2 |
4,67 |
30 |
8,71 |
|
3 |
4,77 |
31 |
8,91 |
|
4 |
4,88 |
32 |
9,11 |
|
5 |
4,98 |
33 |
9,32 |
|
6 |
5,10 |
34 |
9,53 |
|
7 |
5,21 |
35 |
9,74 |
|
8 |
5,33 |
36 |
9,96 |
|
9 |
5,45 |
37 |
10,19 |
|
10 |
5,57 |
38 |
10,42 |
|
11 |
5,70 |
39 |
10,65 |
|
12 |
5,83 |
40 |
10,89 |
|
13 |
5,96 |
41 |
11,14 |
|
14 |
6,10 |
42 |
11,40 |
|
15 |
6,23 |
43 |
11,65 |
|
16 |
6,37 |
44 |
11,91 |
|
17 |
6,52 |
45 |
12,18 |
|
18 |
6,66 |
46 |
12,46 |
|
19 |
6,82 |
47 |
12,74 |
|
20 |
6,97 |
48 |
13,02 |
|
21 |
7,12 |
49 |
13,32 |
|
22 |
7,29 |
50 |
13,62 |
|
23 |
7,45 |
51 |
13,93 |
|
24 |
7,62 |
52 |
14,24 |
|
25 |
7,79 |
53 |
14,56 |
|
26 |
7,97 |
54 |
14,89 |
|
27 |
8,15 |
55 |
15,23 |
The result thus obtained shall be corrected for temperature by increasing it by 0,1 for each degree Centigrade the temperature reading is below 20℃ Centigrade and by decreasing it by 0,1 for each degree Centigrade the temperature is above 20℃ Centigrade.
The test shall be carried out in duplicate without interruption, with separate quantities of the original milled sample and if the two results thus obtained do not differ by more than 0,3 the average of the two results shall be taken as the percentage moisture content of the sunflower seed from which the sample was taken. If the results of the two determinations differ by more than 0,3 the determination shall be repeated with further quantities of the original milled sample until two results are obtained which do not differ by more than 0,3.
Care shall be taken that the mill used for the grinding of the sample, the jar used for mixing the sample and the pressure cell of the apparatus are clean and dry before each determination is commenced. The moisture meter has to be in equilibrium with the temperature of the ambient air in order to obviate the generation of thermo-electric currents in the instrument which may cause errors in the dial reading. For this reason it is imperative that the moisture meter shall remain in one position for an appreciable time before a moisture test is carried out. If for some special reason the moisture meter has to be moved to another position or some other locality, it shall be left undisturbed for at least one hour in the new position to allow the instrument to come into thermal equilibrium with the ambient air before a moisture test is carried out. If it is not possible to affix the thermometer to the case of the instrument, it shall be placed in a convenient horizontal position on top of the apparatus at least 15 minutes before a moisture test is started. In those cases where the thermometer can be affixed to the apparatus but does not remain in that position permanently, it shall be placed in that position at least 15 minutes before commencement of a moisture test.
When a moisture determination is made by means of this method, care shall be taken that the apparatus is in good working order by short circuiting the two top-most sockets on the main apparatus with a short piece of wire and turning the switch to “zero” and adjusting the galvanometer pointer until it is opposite the horizontal line. After the switch has been returned to “Read” the reading on the dials, taken in the manner prescribed above, shall be approximately 60. The wire shall then be removed. Thereafter the clamp shall be connected electrically with the main apparatus as prescribed, the switch turned to “zero”, the galvanometer pointer adjusted to the position opposite the horizontal line and the base of the test cell kept in its normal position in the clamp. A piece of metal wire or silver paper (tin foil) shall be placed across the exposed electrodes (the metal parts) of the test cell and pressed down to cause a short circuit. After the switch has been turned to “Read” the dial reading, taken in the manner prescribed, shall be approximately 60. Thereafter the base and the insular ring of the test cell shall be placed in the clamp and screwed down without the plunger until they just fit tightly, the switch turned to “zero” and the galvanometer pointer adjusted to the position opposite the horizontal line. After the switch has been turned to “Read” the reading on the dials in this instance would be nil or lower but, if the reading is higher than nil, the base of the test cell may be exposed to sunlight or reasonably warm air for a few minutes after which the test shall be repeated.
(6) Cleaning of test cell: It is essential that the test cell shall be thoroughly cleaned after each moisture determination as follows—
(a) for readings below 40-rub the test cell thoroughly clean with a clean, dry cloth; and
(b) for readings above 40-clean the test cell thoroughly with undiluted “Teepol” or other cleansing medium and dry thoroughly with a clean, dry cloth.
(7) After the test cell has been cleaned it shall be left for at least two minutes to ensure that no moisture has adhered to it and also to let the temperature of the test cell return to normal.
(8) Cleaning of mill: After the samples of sunflower seed have been ground, the mill must be thoroughly cleaned, using “Teepol” or other cleansing medium and rubbed dry with a clean, dry cloth.