Flaxseed: Determination of dockage

Definitions

Dockage is assessed and recorded to the nearest 0.1%.

Dockage is defined under the Canada Grain Act as “any material intermixed with a parcel of grain, other than kernels of grain of a standard of quality fixed by or under this Act for a grade of that grain, that must and can be separated from the parcel of grain before that grade can be assigned to the grain”. Dockage is removed by the following cleaning procedures described in this chapter.

The sample as it arrives is referred to as the uncleaned or dirty sample. Its weight is the gross weight of the sample. Dockage is assessed on the gross weight of the sample.

Dockage is assessed in two stages.

1. Follow Normal cleaning procedures, using the Carter dockage tester.
2. Follow procedures for Cleaning for grade improvement. This cleaning can be done at any time after the cleaning assessment has been completed.

Dockage not reported

Normal cleaning procedures

1. Set up the Carter dockage tester as follows:

   Carter dockage tester specifications

   Feed control	#4
   Air control	#3
   Riddle	numberNo. 000
   Top sieve	Blank tray
   Centre sieve	None
   Bottom sieve	None
   Sieve cleaner control	Off

2. You need the following hand sieves: numberNo. 4.5 round-hole sieve, and one wire sieve, depending on the size of the flaxseed and the nature of the material to be removed.

   Round-hole sieves

   • numberNo. 4.5

   Wire sieves

   • numberNo. 4x14
   • numberNo. 3x16
3. Using a Boerner-type divider, divide the uncleaned sample to obtain a representative portion.
   • Official samples shall be at least 1 kg.
   • Unofficial samples shall be at least 1 kg.
4. For hand sieving use approximately 250 g per sieving
   1. Sieve each portion over the appropriate wire sieve until maximum cleanout has been achieved.
   2. Sieve each portion over the numberNo. 4.5 RH sieve until maximum cleanout has been achieved.
5. Combine the separated 250-g portions.
6. Turn on the Carter dockage tester.
7. Pour the entire working sample into the hopper.
8. After the sample has passed through the machine, turn off the machine.
9. Lightly snap the retainer rod of the aspiration pan to loosen material gathered on the air screen
10. Using a Boerner-type divider, divide not less than 20 g from the cleaned working sample.
11. From the 20-g portion, determine the percentage by weight of inseparable material.
12. Determine dockage, using the list under Composition of dockage.

Composition of dockage

Dockage includes

• Material remaining on top of the wire sieve
• Material that passes through the numberNo. 4.5 round-hole sieve
• Material removed by aspiration
• Material that passes over the numberNo. 000 riddle
• Soft earth pellets handpicked from the cleaned sample
• Inseparable material up to established grade tolerances handpicked from the clean sample
• Material removed by Cleaning for grade improvement

Primary elevator samples, commercially clean

Samples exiting primary elevators are commercially clean when the net dockage does not exceed 2.5% of the sample weight. Commercially clean samples exiting primary elevators can have up to 0.5% for broken and reasonably sound flaxseed deducted from the gross weight of the dockage. There is no deduction applicable to producer deliveries or submitted samples.

Primary elevator samples, not commercially clean

In not commercially clean samples exiting primary elevators there is no allowance for broken and reasonably sound flaxseed.

Sample grades

In sample grades, inseparable admixture is not added to dockage. Where the inseparable material exceeds 2.0% of the sample by weight, the admixture becomes a reason for the sample grade and is recorded in remarks.

Rejected account stones

In samples that grade Rejected (basic grade) Account Stones, dockage includes inseparable material handpicked from the clean sample up to the tolerance.

Cleaning for grade improvement

If the grade of a sample can be improved by additional cleaning, perform the cleaning and add the additional material to dockage. Cleaning for grade improvement can be done at any time after the cleaning assessment has been completed, including on export.

1. After the cleaning assessment has been completed, examine the material to be removed and select your equipment according to the material you want to remove. See the table Cleaning for grade improvement—Flaxseed for the list of equipment.
2. Sieve the material by hand or pass it through the Carter dockage tester, depending on the material.

   Important: When you use a hand sieve, move the sieve from left to right 30 times, using a sifting motion. One time is one complete motion from the centre, to one side, to the other side, and back to the centre. The total distance from left to right is 20 cm, or about 8 inches.

3. Weigh the additional dockage and add it to the original dockage.

Optional analysis

Where a shipper requests special cleaning of a carlot of grain at a terminal elevator, and the elevator manager agrees, dockage material will be analyzed for the presence of grain. The percentage and grade of any grain contained in the dockage will be reported.