ISO 5682-4:2021

Overview

ISO 5682-4:2021 specifies standardized test methods for agitation performance in sprayer tanks used to apply plant protection products and fertilizers. It defines how to prepare test suspensions, sample from tanks and nozzles, measure sample concentrations (by evaporation to constant weight), and calculate mean concentrations and deviations. The standard applies to agricultural sprayers but excludes manually operated knapsack sprayers, aircraft, and UASS (unmanned aircraft system) sprayers.

Key topics and technical requirements

• Test setup and equipment
  • Measuring equipment shall comply with ISO 5682-1:2017.
  • Evaporator scale: 0–100 g range, max error 0.001 g.
  • Scale for test material: max error 0.1% of measured value.
• Test material and dosing
  • Example test material referenced: BASF ASP® 602 (informative).
  • Typical dosing: 5 g of test material per litre of tank nominal volume (as specified in the method).
• Sampling methods
  • Tank samples taken at 90%, 50% and 10% of nominal tank volume (minimum two samples per level).
  • Sample size: 20–100 ml; each sample analyzed individually.
  • Nozzle or feed-line sampling during spraying after re-agitation; first sample at spray start and periodic samples according to tank size.
• Measurement method
  • Determine concentration S = (mass of dried sample) / (mass of liquid sample) by evaporating to constant weight (oven 90–120 °C suggested).
  • Total measurement error for concentration shall be within 1%.
• Sprayer operating settings
  • Horizontal boom sprayers: 4 L·min⁻¹ per metre of swath width (or 50% of sprayer max if not designed to meet recommendations).
  • Bush/tree sprayers: 1.5 L·min⁻¹ per nozzle.
• Test sequence and calculations
  • Fill procedure: fill to 50%, add test material, fill to nominal volume, agitate 10 min, sample, settle 16 h, re-agitate 10 min, re-sample, then spray while sampling.
  • Compute mean tank concentrations after initial and re-agitation and percentage deviations per provided formulas.

Applications

• Performance verification of tank agitation systems to ensure homogeneous suspension of pesticides/fertilizers.
• Product development and acceptance testing for sprayer manufacturers and OEMs.
• Independent test laboratories and certification bodies performing conformity assessments.
• Research and development for formulation compatibility with agitation systems.

Who should use this standard?

• Agricultural machinery manufacturers and design engineers
• Test labs, certification bodies, and compliance officers
• Agricultural extension services and research institutions
• Regulators assessing application equipment performance

Related standards

• ISO 5681 - Equipment for crop protection - Vocabulary
• ISO 5682-1:2017 - Spraying equipment - Test methods for sprayer nozzles

This standard helps ensure consistent, reproducible testing of sprayer tank agitation-critical for accurate application rates, operator safety, and effective crop protection.