What is the purpose of calibrating application equipment?
- To find out which pests are present on the site
- To check that the product has not passed its shelf life
- To make sure it delivers the intended amount evenly over the target
- To remove residues left from the previous product
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C. To make sure it delivers the intended amount evenly over the target
Calibration measures and adjusts the output so the labeled rate is actually applied. Too little gives poor control; too much is illegal, wasteful and may injure the crop or leave excess residue. Removing old residues is cleaning, not calibration.
Reference: Core Manual: Application Procedures (calibration)
Which nozzle tip material resists wear the longest when spraying abrasive wettable powders?
- Brass
- Ceramic
- Aluminum
- Nylon
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B. Ceramic
Ceramic and hardened stainless steel or tungsten carbide tips hold their orifice size far longer under abrasive sprays. Brass is inexpensive but soft, so it wears quickly and output rises.
Reference: Core Manual: Application Procedures (nozzles)
A boom sprayer has nozzles spaced 20 in. apart. Each nozzle delivers 0.40 GPM and the sprayer travels at 6 MPH. Use GPA = 5940 x GPM / (MPH x W), where GPM is the output of one nozzle and W is the nozzle spacing in inches. What is the application rate?
Answer in GPA.
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19.8 GPA
GPA = 5940 x 0.40 / (6 x 20) = 2376 / 120 = 19.8 GPA.
Reference: Core Manual: Application Procedures (calibration); GPA = 5940 x GPM / (MPH x W)