Stihl Sr 420 - Metering Unit

23SR 340, SR 420
English / USA
Step 4:
Determine 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 it will be during the real run
described below. Determine the
distance walked in one minute.
Also use the trial run to check the
selected working width. In the case of
low-growing crops, the best working
width is 4-5 m. The working width should
be marked with stakes.
Dividing the distance 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
1min
Step 5:
Determine discharge rate
The setting of the metering knob is
calculated as follows:
V
a
(l) x v
b
(m/min) x b(m)
–––––––––––––––––––––– = V
c
(l/min)
A (m
2
)
V
a
= Quantity of solution
v
b
= Walking speed
V
c
= Discharge rate
b = Working width
A = Area
Example:
The values determined in Steps 1-4 and
a working width of 4 m produce the
following discharge rate (setting of
metering knob):
144 l x 10 (m/min) x 4 m
–––––––––––––––––––– = 1.6 l/min
3,600 m
2
Hectares (ha) have to be converted into
m
2
(ha x 10,000 = m
2
).
: The stop cock (1) is closed when the
lever is upright.
: The stop cock (1) is open when the
lever is parallel to the hose.
: Adjust the discharge rate with the
metering knob – not the stop cock.
Metering Unit