How to Guide

ManualsBrandsLesco ManualsOutdoor Tools & EquipmentPro 50 Broadcast Fertilizer Spreader

Spreader Calibration

TO CALIBRATE A SPREADER,

FOLLOW THESE STEPS:

Check the spreader discharge holes with the operating

lever in the closed position. If the discharge holes are not

fully closed, thread the upper jam nut on the operating

leverrod further up the rod. Tighten the lower lock nut

and recheck. Repeat this procedure until the holes are

fully closed.

HOW TO ACHIEVE A UNIFORM

DISTRIBUTION PATTERN:

The accurate method for checking pattern uniformity

is to lay out shallow boxes or pans in a row on a line

perpendicular to the direction of spreader travel. Eleven

boxes or pans, two inches high placed on one-foot

centers will provide accurate calibration. To conduct the

test, begin with the pattern slide completely open and

set the rate control arm at the suggested approximate

setting. Make three passes over the boxes, pushing the

spreader in the same direction each time.The product

caught in each box is then evaluated to determine the

distribution pattern. Weighing the product in each box is

the most accurate, but a simpler method is to pour the

contents of each box into a separate small vial or bottle.

Then set the eleven vials or bottles side-by-side in order.

This makes the pattern variation quite visible.

To reduce the amount of discharge to the right side

(operator's right) the pattern slide should be partially

closed and the test repeated until the distribution pattern

is uniform.

TO ACHIEVE THE CORRECT

PRODUCT APPLICATION RATE:

The approximate spreader settings printed on any

product label should only be used as the initial setting for

calibration. Set the rate control arm at this approximate

setting. Using the collection boxes or pans, make a single

pass over them to determine the effective pattern width.

The effective pattern width is twice (2x) the distance to

the point where the rate drops to one-half the average

rate at the center.

Example: If the product in the vials from the center boxes

averages two inches in depth, count out to the vial which

has one inch of product. If this is the fifth vial from the

center and the boxes were on one-foot centers, the

effective pattern width is ten feet (2x5ft.).

Knowing the effective pattern width (ten feet), measure

out a line a distance to equal 1,000 sq.ft. (10ft. x 100ft.

= 1,000 sq. ft.). Weigh 20 lbs. of product and place it

in the spreader hopper and spread it over the distance

necessary to equal 1,000 sq.ft. (100ft.). Then weigh the

product left in the hopper and subtract this amount from

the amount with which you started. The result is the

application rate for this product in pounds per 1,000 sq.

ft. that your spreader is currently adjusted to disperse.

Adjust the rate control arm up or down as needed and

repeat this procedure until the correct application rate is

achieved.

Spreader calibration is simplified using the LESCO

Professional Granular Applicator Calibration Kit LESCO No. 009952.

Two items must be considered when calibrating a spreader. The first is the distribution pattern of the spreader. That is,

the pattern the product makes as it strikes the ground after being thrown out by the spreader's impeller. There are many

factors which affect the distribution pattern of a rotary spreader and some of them relate directly to the product. For this

reason, we recommend that the spreader be calibrated separately for every product to be applied. Spreader calibration

should be checked at least once a month, or more often when the spreader is used frequently.

The second item is the product application rate, that is the amount of product applied per thousand square feet. This

is important because over-application can be costly and may cause plant injury, while under-application will reduce the

effectiveness of the product.

Summary of content (2 pages)

PAGE 1
Spreader Calibration Spreader calibration is simplified using the LESCO Professional Granular Applicator Calibration Kit LESCO No. 009952. Two items must be considered when calibrating a spreader. The first is the distribution pattern of the spreader. That is, the pattern the product makes as it strikes the ground after being thrown out by the spreader's impeller. There are many factors which affect the distribution pattern of a rotary spreader and some of them relate directly to the product.
PAGE 2
Spreader Calibration TO USE THE LESCO CALIBRATION GAUGES SPREADER TIPS: 1. Always push the spreader; do not pull. The LESCO Calibration Gauges provide a series of ”steps”, numbered in 1/32-inch increments, that will allow you to ”fine-tune” the LESCO spreader. Once you have calibrated your LESCO rotary spreader for the product chosen, open the operating lever and insert the calibration gauges until you determine which step fits tightly into one of the open holes in the hopper bottom.