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 following the cleaning procedures described in this section of the guide.
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.
▲ Important: Dockage is not reported for samples graded as
▲ Important: Wear gloves and a mask to handle any samples that you suspect may contain hazardous substances.
Samples that are commercially clean do not go through the Carter dockage tester.
1. Using a Boerner-type divider, divide the uncleaned sample to obtain a representative portion.
2. Sieve the samples over the No. 8 round-hole hand sieve, using approximately 250 g at a time, to remove all readily removable material.
3. Set up the Carter dockage tester as follows:
| Feed control | #10 |
|---|---|
| Air control | #7 |
| Riddle | none |
| Top sieve | blank tray |
| Centre sieve | none |
| Bottom sieve | none |
| Sieve cleaner control | off |
4. Turn on the Carter dockage tester.
5. Pour the sample into the hopper.
6. After the sample has passed through the machine, turn off the machine.
7. Lightly snap the retainer rod of the aspiration pan to loosen material gathered on the air screen.
8. Determine dockage, using the list under Composition of dockage.
▲ Important: Return all pieces of soybeans or whole soybeans, sclerotinia, ergot, weed seeds or other grains removed by aspiration to the sample where they are assessed as grading factors. Aspiration is used only as an aid to help speed up the removal of lightweight dockage material from the sample.
Where a shipper requests special cleaning of a carlot of grain at a terminal or transfer 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 and elevator stocks will be adjusted on the basis of the analysis. Agreement of the shipper and unload elevator must be conveyed to the CGC in writing prior to the analysis being performed.