Overview
ISO 16236:2013 specifies a standardized test method to determine the drainable volume and its concentration remaining in agricultural sprayers after the recommended cleaning procedure. The standard applies to crop protection and liquid‑fertiliser sprayers (both new and in‑use) and defines how to contaminate, rinse, collect and analyse residual liquids from the tank outlet and other drain points (e.g. suction filter, filling connection). ISO 16236:2013 supports safe emptying of spray tanks, accurate evaluation of cleaning effectiveness, and harmonised reporting of residual contamination.
Key topics and technical requirements
- Test liquid and tracer: preferred tracer is fluorescein sodium (extra pure) at ~0.0001% (≈1 mg/L). Other tracers allowed if equivalent measurement performance is demonstrated.
- Environmental/test conditions: test and air temperature 5 °C to 30 °C; relative humidity > 30%.
- Contamination procedure: fill tank to ≥10% of nominal volume, add tracer with agitator(s) running, operate normal spraying functions to contaminate hydraulic circuit and internal parts.
- Rinsing and emptying: empty tank by normal spraying practice, continue pump for 1 min ± 5 s after nozzle flow collapses; run rinsing system per operator manual or use three rinse portions (total ≥10% of nominal tank volume if no rinsing system).
- Sampling and measurement: take representative samples ≥50 ml from tank and each collected outlet container; repeat the full test at least three times.
- Accuracy and repeatability: tracer concentration determinations with maximum error ±0.01% of original tank concentration; coefficients of variation for measured volumes and concentrations should not exceed 15% (repeat test if exceeded).
- Calculations and reporting: calculate total drainable volume, tracer mass in drained liquids, mean values, coefficients of variation, and the fraction (%) of residual concentration relative to the original tank concentration. Annex A lists minimum test report content.
Applications and who uses it
ISO 16236 is useful for:
- Sprayer manufacturers - validation of tank and hydraulic designs, rinsing systems, and product claims.
- Test laboratories and certification bodies - standardized procedure for performance testing and compliance reporting.
- Regulators and auditors - assessing environmental and operator exposure risks from residual spray tank liquids.
- Agricultural service providers and equipment inspectors - troubleshooting cleaning procedures and recommending best practices.
- R&D and quality teams - benchmarking cleaning systems and improving spray system maintenance.
Keywords: ISO 16236:2013, drainable volume, sprayers, crop protection equipment, test method, rinsing, fluorescein, spray tank residue, agricultural sprayers.
Related standards
- ISO 13440 - determination of total residual volume in sprayers
- ISO 22368‑1 to ‑3 - test methods for evaluation of sprayer cleaning systems (internal/external cleaning)