Netafim NETAJET 4G, Руководство по установке

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NETAJET
™
4G INSTALLATION MANUAL 35
DOSING CALIBRATION
The process of calibrating the NetaJet™ 4G dosing channels is carried out in three stages:
1. Calculation of dosing channel opening percentage
To finely calibrate the NetaJet™ 4G dosing channels in order to achieve homogeneous and stable dosing,
perform the following calculation for each dosing channel (fertilizers and acids) to determine the amount of
suction reduction needed to attain the required fertilizer/acid flow rate.
Flow rate of the largest irrigation shift
Dosing ratio of a single fertilizer/acid
Result: a single fertilizer/acid flow rate
Result: target Rotameter reading
EXAMPLE
=
X
m
3
/hr
l/m
3
l/hr
l/hr
X 1.25 =
120
3
360
450
Metric units
EXAMPLE
X 0.06 =
X
GPM
US gal/1000 US gal
GPH
GPH
X 1.25 =
500
15
45
56
US units
X 0.06 =
X
GPM
US gal/1000 US gal
GPH
GPH
X 1.25 =
=
X
m
3
/hr
l/m
3
l/hr
l/hr
X 1.25 =
Flow rate of the largest irrigation shift
Dosing ratio of a single fertilizer/acid
Result: a single fertilizer/acid flow rate
Result: target Rotameter reading
DEFINITION
Dosing ratio =
The quantity of fertilizer/acid (l)
1 m
3
irrigation water
DEFINITION
Dosing ratio =
The quantity of fertilizer/acid (US gal)
1 THG (1000 US gal) irrigation water
NOTE
The Rotameter's scale is calibrated by the manufacturer for measurement of the flow rate of water
(H
2
O). Certain inacuracies may be observed when measuring the flow rates of liquids with different
densities, such as fertilizers and acids.
2. Simulation test with a 10-liter (2-US-gallon) bucket of water
Instruments needed
• Good-quality portable EC and pH sensors, finely calibrated
• Calibration solutions for EC and pH
• Bucket with a scale for up to 10 liters (2 US gallons)
• Measuring tube or syringe with a scale for up to 100 cc (1 oz)
• Clean (preferably distilled) water for cleaning sensors during calibration
• Blotting paper for cleaning and drying
The client prepares the fertilizer solutions and the acid solution (if required) in the stock tanks according to
the recipe advised by the agronomist/consultant.
ATTENTION
Ensure that the fertilizers and acid solutions in the stock tanks have been thoroughly agitated
before starting the simulation.