Mixed grain: Grading

Important definitions

Net weight of sample
The sample after cleaning and removal of dockage is referred to as the cleaned sample. Its weight is the net weight of the sample. For grading, percentages by weight refer to percentages of the net weight.
Hazardous substances in samples
Wear gloves and a mask to handle any samples that you suspect may contain hazardous substances. Hazardous substances are defined in section 1 of the Canada Grain Regulations as “any pesticide, desiccant or inoculant”.
Processed sample
An unofficial sample of grain declared to be conditioned or cleaned to meet end user specifications, and whereas, the determination of dockage and/or determination of commercially clean are not performed or reported.
Rounding rules
Rounding rules are outlined in schedule 3 of the Canada Grain Regulations. When official inspection results are expressed numerically, they should be expressed to the same decimal precision as the applicable tolerance in the primary and export grade determination tables.

Representative portion for grading

All grading is done on representative portions divided down from the clean sample, using a Boerner-type divider.

The optimum representative portion is the representative sample size within the minimum and maximum range used to obtain the most accurate result when assessing an objective factor. It is determined by taking into consideration the tolerance and concentration of the objective factor being assessed

Representative portion of mixed grain for grading (in grams)
Grading factor Sample portion size range
Minimum Maximum
Broken 25 g 50 g
Ergot 500 g working sample
Excreta working sample working sample
Fertilizer pellets working sample working sample
Fireburnt working sample working sample
Fusarium damage 25 g 100 g
Heated 25 g 100 g
Large seeds 100 g 250 g
Odour working sample working sample
Sclerotinia sclerotiorum 500 g working sample
Soft earth pellets working sample working sample
Stones working sample working sample
Treated seed working sample working sample