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© TrynEx International 2014 F51509 REV-A140506
Calibration Instructions
To calibrate your spreader, you will need: Notepad, Stopwatch, Tape Measure, Scale, Plastic Tub, and an area for measuring spread width
Here is the equation used:
Desired Application Rate = Output ÷ (Walking Speed x Spread Width)
lbs/ft
2
lbs/min ft/min ft
When calculating, the desired application rate needs to be converted to pounds-per-square-foot.
To Convert...
Pounds-per-Acre, multiply by 43,600
Pounds-per-Thousand-Square-Feet, multiply by 1000
Output is measured in pounds per minute. This is found by putting a known amount of material (five pounds) into the hopper (after setting the
gate with the gate stop) and measuring how long it takes for the material to flow out of the hopper. To convert this time into pounds-per-min
-
ute, divide the pounds by the time (minutes). Seconds should be converted to minutes (the result is a decimal fraction).
The speed is required in feet-per-minute. 1 mile per hour is equal to 88 feet per minute. To maintain a consistent application rate, you will
need to walk at a speed that you can maintain across the whole spreading area.
Set the open position of the gate with the Gate Stop. With the gate closed, pour five pounds of material into the hopper. Make sure the plastic
tub is below the spreader where it can catch material flowing from the gate. Open the gate and measure how much time it takes for all the
material to come out of the Spreader. Record this. Repeat this procedure until you have a reading for each of the gate settings on the chart:
3, 6, 9, 12, 15, 18, 21, 24, 27, and 30.
Using the times obtained, calculate the pounds-per-minute – record the result in the Calibration Chart.
Measure the spread width by walking a short distance at approximately each speed (220 ft/min). When measuring, exclude the thin edges
where the coverage thins out, this will be your ‘effective spread width’. Record the resulting width in the chart.
All seed and fertilizer mixtures, regardless of physical similarities, flow and spread differently. Therefore, your spreader should be calibrated
specifically for each material you are spreading. Use the charts in this manual to record calibration data for your spreader for materials you
commonly use.
MATERIALS NEEDED
MATH
COLLECTING AND RECORDING DATA
Find the required application rate from the product label. Decide the speed you will maintain and your spread width (use the chart below as a
guide). Set the Spreader Speed based on the data you have collected and recorded in the chart to obtain the spread width.
Use the equation below to find the output and the values in the chart to find the gate setting.
Required Output = Application Rate x Walking Speed x Spread Width
lbs/min lbs/ft
2
ft/min ft
Find the gate setting that matches the required output using the values you recorded in the chart. You may need to adjust your walking speed
slightly.
CONFIGURING SPREADER
Gate Stop @ 20
Gate Lever closed
