Calculating Required Quantity Of Solution - Stihl SR 430 Instruction Manual

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Calculating Required
Quantity of Solution
Determining surface area (m
In the case of ground crops, simply
multiply the length of the field by its
width.
The surface area of high-growing plants
is calculated approximately by
measuring the length of the rows and the
average height of the foliage. The result
is multiplied by the number of rows and
then by two if both sides have to be
treated.
The surface area in hectares is obtained
by dividing the number of square meters
by 10,000.
Example:
A field 120 meters long and 30 meters
wide has to be treated with a pesticide.
Area:
2
120 m x 30 m = 3,600 m
3,600 / 10,000 = 0.36 ha
Determining quantity of active ingredient
Refer to the instructions supplied with
the active ingredient to determine:
Required quantity of active
–
ingredient for 1 hectare (ha).
Concentration of active ingredient
–
(mix ratio).
18
Multiply the required quantity of active
ingredient for 1 hectare by the area
determined in hectares. The result is the
quantity of active ingredient required for
2
) the area to be treated.
Example:
According to the maker's instructions,
0.4 liters of active ingredient are
required per hectare to obtain a
concentration of 0.1%.
Quantity of active ingredient:
0.4 (l/ha) x 0.36 (ha) = 0.144 l
Determining quantity of solution
The quantity of solution required is
calculated as follows:
T
W
x 100 = T
K
T = Quantity of active ingredient in
W
liters
K K = Concentration in %
T = Required quantity of solution in
B
liters
Example:
The calculated quantity of active
ingredient is 0.144 liters. According to
the maker's instructions, the
concentration is 0.1%.
Quantity of solution:
0.144 l
x 100 = 144 l
0.1 %
B
Determining walking speed
Carry out a trial run with the machine
fueled and the container filled with
water. Operate the spray tube (swing it
back and forth) as for the real run
described below. Determine the
distance walked in one minute.
Also use the trial run to check the
selected working width. The best
working width for low-growing crops is
4–5 m. Mark the working width with
stakes.
Dividing the distance walked in meters
by the time in minutes gives you the
walking speed in meters per minute
(m/min).
Example:
The distance covered in one minute is
10 meters.
Walking speed:
10 m
= 10 m/min
1 min
Determining discharge rate
The setting of the metering unit is
calculated as follows:
V (l) x v (m/min) x b(m)
a b
2
A (m )
V = Quantity of solution
a
v = Walking speed
b
V = Discharge rate
c
b = Working width
A = Area
Example:
SR 430, SR 450
= V (l/min)
c