Buying a used sprayer: residues, individual nozzle results and licensed controls
Buying a used sprayer requires separate evidence for residue control, liquid-system performance, calibration, electronics and the vehicle or tractor connection. A tank that looks clean does not establish that previous products have been removed, and clear water can become contaminated when introduced into equipment with residues. Resolve the cleaning history, protective equipment and contained test location before commissioning a water test under the machine’s instructions. Iowa State’s calibration guidance compares each nozzle with its desired output, which matters when an average appears correct but individual outlets differ. The purchase also includes the pump, plumbing, boom, sensors, display and any licensed functions, not just the tank and chassis. Record what is installed, what the permitted tests demonstrated and what still needs diagnosis. Then obtain quotations for repairs and missing equipment. A current software screen or a boom that folds once cannot establish accurate application, transfer of every activation or the condition of an entire sprayer.
Resolve the cleaning basis before buying a used sprayer
Which cleaning evidence should be obtained before a water test?
Iowa State’s calibration guidance calls for prior residue cleaning, water-only calibration, appropriate protective equipment and a location that avoids harmful runoff. Obtain product-use and cleaning records.
Follow the machine’s applicable cleaning and test instructions. Neither appearance nor a seller’s general assurance establishes the absence of residues that matter for the proposed test and future crops.
Can a buyer assess tank cleaning by smell or entering the tank?
Keep out of the tank. Never inhale residues to judge cleaning.
Arrange the model- and product-applicable inspection and cleaning with competent personnel and the required protective and containment measures. Treat contaminated equipment and wash or test liquid according to their actual requirements; adding clean water does not independently establish that discharge will be harmless.
Read individual catches against the desired output
| Outlet | Catch | Difference from target |
|---|---|---|
| Low example | 0.35 US gal | 12.5% below |
| High example | 0.45 US gal | 12.5% above |
| Pair average | 0.40 US gal | At target despite both individual deviations |
How should an individual catch result be compared with the target?
Assume the desired nozzle output is 0.40 US gallon per minute and a one-minute catch yields 0.45 US gallon. The excess is 0.05 US gallon, or 12.5%. This is a flow-check example, not a pesticide-rate recommendation; use the actual nozzle, application settings, product label and approved information to establish the intended target.
What does Iowa State’s ten-percent guidance mean for a suspect nozzle?
The Iowa State article recommends replacing a nozzle more than 10% away from desired flow, with low-output nozzles checked, cleaned and retested first. Check the cause before cleaning or replacing nozzles. The criterion concerns the desired output, so a set with matching catches can still be unsuitable if every nozzle produces the wrong flow.
How can an average conceal two poor individual results?
Against an assumed 0.40 US gpm target, 0.35 and 0.45 US gpm average exactly 0.40, but both deviate by 12.5%; accepting only the pair’s mean would conceal a low-flow outlet and a high-flow outlet needing their own assessment. Record and investigate each outlet separately.
Inspect the liquid system, boom and control evidence
Does low pressure or pulsing prove that the pump needs replacement?
Record the actual operating settings and test conditions, then have the liquid system assessed for the model’s permitted flow and pressure performance. Investigate supply, configuration and plumbing before pricing a pump. Do not open a pressurised line or price a guessed pump as a confirmed repair without the appropriate diagnosis and safe isolation procedure.
Which boom findings belong in the purchase inspection?
Identify the actual structure, hinges, supports, fold arrangement, height-control equipment and installed nozzle spacing. Commission the prescribed condition and function checks.
Use the specified supports and isolation. A boom that unfolds does not establish the soundness of every hinge, repaired section, sensor or transport restraint.
What must be verified about the rate controller and flow meter?
Record the component identities, configuration, calibration history and the output independently checked under the intended setup. Displayed rate cannot measure every outlet’s actual delivery. Obtain the manufacturer’s diagnostic procedure and qualified support before changing calibration values or assuming a new display resolves a flow discrepancy.
Verify included electronic functions and the carrier connection
Which electronic functions need written inclusion and transfer evidence?
List the display, receiver, steering, section control, correction services and other fitted functions that matter to the job. Verify licenses, subscriptions and activation-transfer conditions with the provider. A current software version, visible menu or antenna does not establish that every function is activated, transferable and working on the offered sprayer.
How does the inspection change between self-propelled and trailed machines?
The self-propelled package needs the applicable engine, drive, steering, brakes, suspension and running-gear assessment. A trailed machine instead needs its actual drawbar, hydraulic, electrical and control connections matched to the intended tractor, along with its own axle and braking requirements. Inspect carrier condition separately from nozzle performance.
Compare known acquisition work and unresolved condition
What can missing controls and known boom repairs do to the subtotal?
Assume offer A is $40,000 plus $4,000 of compatible controls and $3,000 of identified boom work, reaching $47,000. Assume offer B includes the controls at $45,000 and needs $1,000 of work, reaching $46,000. The figures are hypothetical: compare equal required functions and inspection scope before treating the $5,000 listing-price difference as a saving.
Which remaining costs should stay visible after that comparison?
Add actual delivery, applicable tax, installation, required calibration and other identified preparation. List unresolved contamination, diagnosis and unperformed tests separately.
Their cost has not been established as zero. Equal nozzle output on one test cannot price those gaps or establish a package ready for the products, crops and conditions you intend to use.
What should the buyer be able to decide from the finished inspection?
Whether the actual sprayer can support the intended application and connection requirements, with a documented cleaning basis, costed work and acceptable unresolved condition. Reconcile ownership, service history, support and transport alongside the operating evidence. If a required function or residue concern remains unassessed, obtain that resolution before relying on the machine’s advertised readiness.
See application and nozzle calibration and Sprayers: sprayer configurations for the equipment being considered. Within the Equipment buying: purchase guides, review inspection scope, technical support and Checking a machine for liens and theft: ownership evidence.