Duncan DO 07185, Owner'S Manual

Page: 17 / 62

15
Basic Calibration Procedure (Continued)
Seed Calibration Procedures (Continued)
Hand Crank Turns for Seed Rate Calibration
The tables represented below are for arable conditions ( worked
ground ) and are calculated to indicate an average situation. If
there is any doubt as to the accuracy of these figures for the
conditions, it is advisable to run at least 1 of the 2 checks on the
calibration figures listed. Refer Page 16 (
Recalculating the
Constant ) and/or Page 17, ( Wheel Slip Deviations ). Check and
record which tyres are fitted to your drill, to ensure use of the
correct Hand Crank Turn and Constant figures.
9 Weigh the seed collected during the test in kilograms.
Caution: Scales must be accurate to 1 gram, as any error will be
multiplied by either 20 or 80, giving inaccurate calibration results.
10 Calculate the seed rate by multiplying the kgs previously collected
x 80 (1/80th ha method, refer Table 6) or x 20 (1/20th ha method,
refer Table 7) depending on the requirement. If the resultant
calculation does not produce the desired seed rate use the
enclosed seed rate calculator disc to determine the correct
gearbox setting.
Refer Use of Seed Rate Calculator Page 16
Suggestion: To be on the safe side and until confidence has been
gained with the method of calibration it is advisable to conduct a
second test at the newly determined gearbox setting.
11 Where a coated seed is used it is advisable to check the
calibration after 1 hectare as dressings can tend to create a
coating on the seed metering wheels thus changing the the
flowing properties of the seed which in turn alters the seed rate.
For 1/80 Hectare (125m 2 ) Calibration
Seed Rate = Actual Seed Collected (kg) x 80
For 1/20 Hectare (500m 2 ) Calibration
Seed Rate = Actual Seed Collected (kg) x 20
Table 6
Table 5
Table 7
Sowing Width Turns for Turns for
(m) 1/80 Hectare 1/20 Hectare
2.25 25.5 102
Pt. No. 67376
Issue 0207