Verify Metering-1/10 Hectare Stationary Method

As 1900 Commodity Air Carts meter seed, a handle turns on the left-hand side of the machine. This handle turns a certain number of turns per acre. The number of turns is different for every cart. There can be up to 1300 turns per hectare, so the following calculation shows how to figure the number of turns for 1/10 hectare .

IMPORTANT: Metering accuracy is directly related to the amount of product metered out. At least 5 kg of metered product is required to accurately use this method.

For example, 1/10 of an acre of canola is only about 0.5 kg. This cannot be weighed accurately with the scale provided so this method should not be used with this product.

1. Calculate wheel turns for 1/10 ha.

FORMULA:

Number of Wheel Turns for 1/10 ha = 1000 ÷ Seeding Tool Width (m) ÷ Drive Tire Circumference (m)

EXAMPLE:

1900 cart with 9.14 m seeding tool and 28L x 26 R3 tires. Tire circumference from the Drive Tire Chart is 4.775 m.

Wheel turns for 1/10 ha = 1000 ÷ 9.14 m ÷ 4.775 m or 22.9 turns per 1/10 ha.

Drive Tire Chart
Tire Size Tire Circumference (m/rev) Tire Circumference (in/rev)
18.4-26 R3, 10PR 4.191 165
18.4-26 R2, 10PR 4.394 173
23.1-26 R3, 10PR 4.521 178
23.1-26 R2, 10PR 5.029 198
28L-26 R3, 12PR 4.775 188
28L-26 R2, 12PR 5.080 200
30.5L-32 R3, 12PR 5.359 211
30.5L-32 R2, 12PR 5.664 223
20.8R-38 R1, 1 STAR 5.639 222
710/70R-38 R1W, 2 STAR 5.893 232
18.4R-46 R1, 3 STAR 6.020 237
20.8R-42 R1, 2 Star 5.867 231

 

2. Calculate crank turns for 1/10 ha.

FORMULA:

Number of Crank Turns = Wheel Turns x 2.333 x Wheel Sprocket Teeth ÷ Row Space Sprocket

EXAMPLE:

The chain sprocket has 62 teeth and the row space sprocket has 27 teeth.

Crank turns for 1/10 ha = 22.9 wheel turns x 2.333 x 62 teeth ÷ 27 teeth or 123 crank turns per 1/10 ha.

3. Calculate seeding rate.

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Metering accuracy can now be checked quickly by turning the meter crank counterclockwise (same way it runs in field) the calculated number of turns.

Multiply sample weight by 10 to determine actual seeding rate.

EXAMPLE:

5. 2 kg of product is caught after turning the crank 49 1/2 turns. Seeding Rate = 5. 2 kg x 10 = 52 kg per hectare.

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