17
17-1 Product Calibration
You will have to perform a catch and weigh test to establish the flow rate of product, and will need a suitable
container to collect the product being metered and an accurate set of scales to weigh kilograms and grams, and
a timer.
To establish the correct flow rate of product being applied for your bout width, forward speed and
application rate use the below formula;
Method
Use the following formula to establish the flow rate – this is a 1 minute catch test universal for all machines,
products, widths and speeds.
Application rate (kgs/ha) x forward speed (kph) x spread width (metres) = Flow rate in kgs per min
600
Example 1.
The required application rate is 25 kilograms per hectare. The target forward speed is 10 kilometres per hour.
The bout width is 6 metres wide.
25 kgs/ha x 10 kph x 6 metres = 2.5kgs per minute flow rate
600
Example 2.
The required application rate is 5.5 kilograms per hectare. The target forward speed is 12 kilometres per hour.
The bout width is 4.25 metres wide.
5.5 kgs/ha x 12 kph x 4.25 metres = 467 grams per minute flow rate
600
1.
Position a collection container directly underneath ALL outlet pipes to catch the product being calibrated.
2.
Put a small amount of material in the hopper.
NOTE
Do not fill the hopper at this stage as the feed block assembly may have to be removed and the feed
rollers changed to achieve the correct feed rate (kgs/Ha) at the required forward speed (kph)
3.
Perform the catch and weigh test.
a
. Be ready to time the test - switch on the feed rolls – start timing – stop the feed rolls after 1 minute.
b
. Accurately weigh the product metered over the timed period, and compare the weight collected to the
figure indicated by the calibration chart at the end of manual. Increase or decrease the feed roll speed until
you collect the correct amount of product for your rate, width and forward speed.
c.
Use the cab control to select High or Low motor speed range on Vari Speed machines or the High and
Low switch located on the motor guard in combination with the motor speed dial to achieve the rate required
in a 1 minute catch test.
NOTE
Be aware that the Fan Speed on the Air Force Model may effect quantity of material being metered
depending upon the product being applied.
17-2 Calibration catch and weigh test