Operation Fertilizer Spreader Calibration Calibration It is the responsibility of the person using this equip ment to make sure that every type of material is properly calibrated to perform as expected. To achieve a safe and accurate reading for proper material distribution, calibration must take place on a solid flat surface away from drains and livestock areas. Failure to do so causes an over or under application that damages turf areas or gives an ineffective pest control treatment. Any calibration charts contained in this manual are given as a reference point only and must not be used as an absolute condition.
Spending a few extra minutes to calibrate not only saves on wasted materials and time, but also protects turf and other vegetation. Be aware of the following points before operating your spreader in the field. NOTE: To change the spread pattern, adjust the spinner fins. To calibrate the spreader, use a level, open area of pave ment. Set the gate stop in the middle as a starting point. Fill the hopper with the material desired. Turn on the spreader. To achieve desired spread width, adjust spinner speed. Record the spinner speed setting and the resulting spread width. Determine the driving speed while spread ing (in feet-per-minute).
Determine desired application rate (converted to pounds-per-square-foot). To determine the pounds-per-minute that the gate setting must allow, use the following equation. Flow Rates Desired Application Rate (pounds-per-square-foot) x Spread Width (feet) x Speed (feet-per-minute) = Pounds- per-minute. Flow rates of materials change for many reasons: Formulations vary within the same brand or even between brands. Open the gate. The spinner must be operating during this step. Put a bucket or other means of catching material at the back of the spreader. Leave the gate open for one minute. Brush off all excess from the spinner and motor enclosure into the bucket. Weigh the bucket with material.
Subtract the weight of the bucket when empty and record. To achieve the required “pounds-per-minute” rate, adjust the gate based on the result. Once the setting is estab lished, you are ready to spread. Record for future use on the notes page of this manual (example record: when spreading Material XYZ... Spinner speed 50% (width=14 ft.), Drive 3.5 mph (308 fpm), Gate = 13 in.). Formulations vary between batches or dates of manufacture. Humidity causes the material to clump and flow poorly. Poor spreader maintenance causes flow changes. Slide stop has moved or has been calibrated to another type of material. Human error causes rate miscalculation.
Items Needed for Calibration A way to catch the material for weighing. Begin spreading with the vehicle speed, gate setting, and spinner speed used in your calculations. A device to measure distance. A scale to weigh your product. A stop watch or other device to measure time. Conversion To convert pounds per 1000 sq. ft. to pounds per acre, multiply your rate by 43.6. To convert miles-per-hour to feet-per-minute, multiply miles-per-hour by 88. Other Important Information: 1 acre is equal to 43,560 sq. ft. Ground speed is import ant to keep in mind when doing calculations, convert miles-per-hour to feet-per-minute. 13 LP69910 (12/07/2020) 3 CU FT GATOR FERTILIZER SPREADER