Application Equipment, Calibration and Application Techniques
Know the tools
Typical structural equipment: compressed-air sprayers (1–3 gallon), backpack sprayers, hand and bulb dusters, bait guns, foam generators, ULV and fogging machines, termite rodding tools and granular spreaders. Each has a working pressure, a nozzle or tip, and a delivery rate that must be measured rather than assumed.
Calibration
Calibration has three steps: measure the output, measure or know the area/time, and convert to the label rate. For sprayers, collect the output in a graduated cylinder for 60 seconds at working pressure. Then use the rate relationship:
Application rate = output ÷ (speed × swath width)
For baseboard and crack work, calibrate by time instead: decide litres per unit of treated length, then time the application.
Worked example: the label calls for 2 L of diluted spray per 10 m²; the sprayer delivers 0.5 L/min. You need 2 ÷ 0.5 = 4 minutes of spraying for each 10 m². For 40 m² you need 8 L and 16 minutes.
Mixing example: label says 30 mL per 4 L of water; for a 12 L tank, 30 × 3 = 90 mL.
Checks: pressure gauge, nozzle wear and pattern, filters and screens, hose and seals, tank cleanliness, triple rinsing between products, and original labelled containers only.
Traps: calibrating once and never again; changing nozzles or pressure without recalibrating; confusing concentrate rate with diluted spray rate; applying extra because "more is better" - which is both illegal and hazardous.
Rule of thumb: calibrate with clean water before every job, and recalibrate whenever you change nozzle, pressure, product or technique.