Sprayer Calibration & Tip Check
Find out what your sprayer is really putting out, spot worn tips, and fix it — with pressure, speed or new tips.
What are you trying to apply?
Three numbers set the flow every tip has to deliver. If you don't know your speed, use the speed check below.
Optional: boom width & tank size (for acres per tank)
Not sure of your speed? Speed check
Mark off a distance in the field, drive it at spraying speed with the tank half full, and time it.
Catch test
Fill with clean water, set your normal pressure, and catch the output of each tip for 30 seconds in a measuring cup. Enter ounces per tip — one tip is a quick check, the whole boom finds the worn ones.
Fix it
After you install new tips
- Replace the whole boom with the same series and size — mixing worn and new tips, or two series, gives an uneven pattern.
- Put a fresh tip strainer behind each tip: 100 mesh for 02 tips and smaller, 50 mesh for 03 and larger. Shop tip strainers →
- Check the gasket or cap seal on each nozzle body while it's apart — a weeping cap drops that tip's output.
- Set the pressure, then re-run this catch test with water. New tips should land within 5% of each other.
- Hold the tips 1–2 ft above a dry surface and look for streaks or heavy edges — a bad pattern on a new tip is usually a strainer or body problem, not the tip.
- Stuck on any of this? Ask Dusty, our help assistant, or call (509) 838-2209.
How to calibrate a boom sprayer
Calibration is checking that what comes out of the boom matches what the label says to apply. Three things set it: the flow of each tip, your travel speed, and the spacing between tips. Get any one of them wrong and you're under- or over-applying — and a sprayer that was dead-on last spring can be 10–15% off this year just from tip wear.
The 30-second catch test
- Fill the tank at least half full with clean water and run it up to your spraying pressure.
- Hold a measuring cup under one tip for exactly 30 seconds. Write down the ounces.
- Repeat across the boom — at least every third tip, all of them if you have time.
- Ounces ÷ 128 × 2 = GPM per tip. Compare each tip to the average: anything more than 10% off is worn (high) or plugged (low).
- Compare the average to the GPM your rate needs. If it's off, adjust pressure, adjust speed, or change tip size — the tool above does the math for all three.
Pressure, speed or tips?
Pressure is the quick fix, but flow only changes with the square root of pressure — to get 10% more flow you need about 21% more pressure, and pushing a tip outside its ideal 30–50 psi band changes the droplet size and the pattern. Speed changes flow one-for-one but may not suit the field. Changing tip size is the right answer when the correction is more than about 15%, and the nozzle selector will pick the size from what we stock.
Common questions
How often should I calibrate my sprayer?
At the start of every season, any time you change tips, speed or pressure, and after any product that's abrasive (suspensions, wettable powders, some fertilizers). A quick single-tip catch test takes two minutes and catches most problems.
When should I replace spray tips?
TeeJet's guideline is when output is more than 10% above a new tip of the same size — a worn tip flows more, not less. Polymer tips wear fastest, stainless and ceramic last longer. If one tip is worn, the rest are usually close behind, so replace the whole boom at once.
Why is one tip putting out less than the others?
Almost always a partly plugged tip strainer or a bit of debris in the tip. Pull the strainer, clean it with a soft brush (never a wire), and re-test. If it's still low, the tip orifice is damaged — replace it.
How do I check my sprayer's ground speed?
Don't trust the tractor's speedometer in soft ground. Mark 200 feet in the field, drive it at spraying speed with the tank half full, and time it: 200 ft in 11.4 seconds is 12 mph. The speed check in step 1 does the conversion.
What size measuring cup do I need?
A 32-ounce cup with ounce markings covers most tips at a 30-second catch. For large tips or a 60-second catch, a quart-plus pitcher. Calibration cups with GPM scales exist, but any accurate kitchen measure works.
Still not sure?
Bring us your catch-test numbers, your speed and your spacing and we'll sort it out over the phone — we do it for customers across the Inland Northwest every spring. Related tools: Nozzle selector · Tank mix calculator · Pump finder · Raven troubleshooting guide.
Call (509) 838-2209