Start / Machinery and application / Spraying, planting and spreading
Enter the masses collected in the trays from one pass and check whether the spreader distributes the fertilizer evenly.
Pre-sizing and estimating tool: the results do not replace a design, calculation, or report signed by a qualified professional, nor verification against the applicable standards.
Technical responsibility. This calculator is under verification. The reference values and examples are hypothetical, to illustrate the calculation, and are not technical references. The user is responsible for the data entered, the choice of parameters, and the use of the results, and must validate them with a qualified professional before any decision, purchase, application, or construction work.
How much fertilizer fell into each collector; highlighted are those more than 20% different from the average.
Percentage difference of each collector; above zero means it receives more than the average.
Drag the controls to simulate data different from what you entered (from 30% less to 30% more) and watch the result change instantly.
Sensitivity of the coefficient of variation to the mass in each collector, and each collector's position relative to the average.
The calculation done in steps, with the values you entered.
The calculation memo gathers this page's inputs, results, equations, assumptions, and references, with fields for project, responsible person, and review. The full report also includes the charts and interpretations, in color. In the print window, choose Save as PDF.
Pass the spreader over the tarp or tray in one pass, and weigh the fertilizer in each of the eight collectors. Enter the masses in grams. The calculator shows the average, the coefficient of variation and the Christiansen uniformity.
Masses of 52, 48, 55, 40, 61, 47, 50, and 44 g.
Mean = 397 ÷ 8 = 49.6 g. Standard deviation = 6.5 g. CV = 13.1%. Sum of absolute deviations = 39.0 g. CUC = 100 × (1 − 39.0 ÷ (8 × 49.6)) = 90.2%.
Because the number of samples gives a reasonable reading of the band in one pass. With fewer collectors, the result varies a lot from one test to another.
They say similar things, but by different routes. The CV uses the standard deviation and the CUC uses the mean deviation. The higher the CUC and the lower the CV, the more uniform the distribution.
Check the setting of the disc or metering system, the height, the forward speed and the uniformity of the fertilizer itself, with broken granules or granules of different sizes.
No. It evaluates one pass. Full calibration requires repeat tests, the working width, and the equipment's actual speed.
Important notice: the Agrocalcs tools make estimates and preliminary sizing based on the data entered and on published engineering methods. They do not replace a design, a calculation report or a report signed by a qualified professional (CREA/ART), nor verification against the applicable technical standards and legislation, such as the Regulatory Standards of the Ministry of Labor. Material and fuel properties vary: check with the manufacturer or with analyses of your process before deciding. By using the site, you agree to the Terms of Use.
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