Procedures and equipment for determining test weight in Canada
Test weight is determined using the 0.5 litre measure, a Cox funnel to standardize the pouring rate, and a striker to level the contents of the container.
|0.5 litre measure||A cylindrical shaped cup with an inside diameter of approximately 90 mm and a height of approximately 77.5 mm. The measure is calibrated to contain 500 mL of water, ± 1 mL, at 20°C.|
|Cox funnel||A funnel with a 3.81 cm opening and a drop of 4.41 cm, from the opening in the funnel to the top of the measure used to uniformly direct the flow of grain into the 0.5 litre cup.|
|Striker||A piece of round hardwood, 2.2 cm in diameter and approximately 23 cm in length.|
|Scale||Any CGC-approved electronic metric scale.|
|Computer interface||For CGC inspection purposes, the electronic scale is connected to a computer that converts the grams in the 0.5 litre measure to grams per hectolitre. If the computer interface is not available, the test weight conversion can be done by utilizing charts provided by the CGC.|
|Test weight conversion charts||Used to convert the weight in grams from the 0.5 litre measure to kg/hL.|
Fill the Ohaus measure to overflowing with the grain to be tested. Ensure the slide is inserted into the Cox funnel.
Pour the contents of the 0.5 litre measure, plus an extra handful, into the Cox funnel. Place the 0.5 litre measure on a solid base. Position the Cox funnel on top of the 0.5 litre measure so that the notched legs of the Cox funnel fit securely onto the measure's rim.
Remove the slide on the Cox funnel quickly so that the grain drops evenly into the 0.5 litre measure. Carefully remove the Cox funnel from the top of the 0.5 litre measure so as not to disturb the grain. Any jarring of the cup at this point will result in compaction of the grain in the 0.5 litre measure and could produce inaccurate results.
Place the hardwood striker on the rim of the 0.5 litre measure and, using three zigzag, equal motions, scalp off the excess grain in the measure.
Pour the grain remaining in the 0.5 litre measure into the scale pan. Determine the weight in grams of the grain in the scale pan. Convert the grams in the 0.5 litre measure to kilograms per hectolitre (kg/hL).