Using Density Meter and Seed Charts

NOTE: Rates are determined by adjusting seed index to settings shown on rate charts in this section.

1. Rates on seed charts are based on a standard density of seed being used. Use density meter (A) to find actual seed density so seeding rate can be more accurately chosen from rate charts.

2. Fill meter bucket with material, tap lightly, level material across top, balance on knife edge and take reading.

3. If actual density differs from standard density (found on "Standard Density Chart", use the following formula to calculate a conversion factor that will be applied to desired seeding rate:

STANDARD DENSITY (from density chart) ÷ ACTUAL DENSITY (from density meter) = CONVERSION FACTOR

4. Multiply desired seeding rate by conversion factor, find new value on rate chart and adjust seed index to match this new rate.

Standard Density Chart
Grain kg/bu (lb/bu) kg/m3 (lb/ft3)
Wheat 27 (60) 774 (48.2)
Barley 22 (48) 619 (38.6)
Oats 15 (32) 413 (25.7)
Rye 25 (56) 722 (45.0)
Peas 27 (60) 774 (48.2)
Soybeans and Navy Beans 27 (60) 774 (48.2)
Buckwheat 24 (52) 671 (41.6)
Sorghum 23 (50) 645 (40.0)
Crested Wheat Grass 10 (21) 271 (16.8)
Alfalfa 27 (60) 774 (48.2)
Millet 23 (50) 645 (40.0)
Flax 25 (56) 722 (44.8)
Sudan Grass 23 (50) 645 (40.0)

 

EXAMPLE: Using 15 cm (6-in.) Rate Chart:

N35976


A-Density Meter

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  • Seed-Wheat
  • Desired seeding rate-90 kg/hectare (81 lb/acre)
  • Standard density for wheat from chart-774 kg/m 3 (48.2 lb/ft 3 )
  • Actual density from density meter-721 kg/m 3 (45 lb/ft 3 )

Calculating conversion factor using formula:

774 kg/m 3 ÷ 721 kg/m 3 = 1.07

(48.2 lb/ft 3 ) ÷ (45 lb/ft 3 ) = 1.07

Multiplying desired seeding rate by conversion factor:

90 kg/hectare x 1.07 = 96.3 kg/hectare

(81 lb/acre) x 1.07 = (87 lb/acre)

Locating closest value to 90 kg/hectare (87 lb/acre) on 15 cm (6 in.) rate chart indicates a meter setting of 16.

For further accuracy, see CHECKING QUANTITIES DRILLED in Operating The Machine section.

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