Calibration

For more detail see: Crop protection: Applying Agricultural Chemicals

Calibration is the output per unit area (e.g., l or kg/ha). It depends on:

• Speed of application
• Equipment output/unit time
• Width of application

You can calibrate by two methods:

Procedure 1 - The total output in a given area

• Measure a given area (e.g., 500 sq m)
• Measure the output from the sprayer or spreader to cover the area

Example 1:

• Test area = 200 sq m
• Output required to cover area = 2 l
• Calibration = 2 l/200 sq m*10,000 sq m/ha = 100 l/ha

Procedure 2 - Combining output per unit time with the time required to cover an area

• Measure the operating speed (e.g., time to cover 100 m) under conditions typical of field application conditions
• Measure the output from the sprayer or spreader in a given time (e.g., 1 minute)
• Measure the width of application

Example 2:

• Speed = 120 s/100 m = 1.2 s/m
• Product output measured = 2 l/min
• Width of application = 4 m
• Calibration = 2 l/min*120 s/(100*4 sq m)* 1 min/60 s * 10,000 sq m/ha = 100 l/ha