Calculating Required Quantity Of Solution - Stihl SR 420 Instruction Manual

If engine does not start
If you did not turn the choke knob to e
quickly enough after the engine began to
fire, the combustion chamber is flooded.
Remove the spark plug – see
N
"Spark Plug".
Dry the spark plug.
N
Open the throttle wide.
N
Crank the engine several times with
N
the starter to clear the combustion
chamber.
Install the spark plug – see "Spark
N
Plug".
Slide the stop switch to # and set
N
the choke knob to e – even if the
engine is cold.
Now start the engine.
N
If fuel tank has been run completely dry
and then refueled
Pull the starter rope several times to
N
prime the fuel system.
SR 420
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).
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 l
W
K = Concentration in %
T = Required quantity of solution in l
B
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 %
Determining walking speed
Carry out a trial run with the machine
fueled and the container filled with
water. Operate the spray tube (swing it
English
B
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