Overview
EN ISO 10248:1999 - titled Fluid fertilizers - De-aeration of suspension samples by film disentrainment (ISO 10248:1996) - is a CEN-adopted international standard that defines a laboratory procedure to remove entrained air from suspension samples of fluid fertilizers prior to physical testing. The standard specifies the film disentrainment technique as the preferred method for de-aeration and clarifies when the method is and is not appropriate.
Key topics and requirements
- Purpose: Provide a repeatable, reproducible procedure for removing entrained air from fertilizer suspensions so that subsequent physical measurements (density, viscosity, particle distribution, etc.) are accurate and comparable.
- Method principle: De-aeration by film disentrainment - air is separated from the suspension when a thin film of liquid travels over a surface, releasing entrained bubbles. (EN ISO 10248 standardizes the use of this principle for fertilizer suspensions.)
- Applicability limits: The procedure is not suitable if:
- The sample contains more than a trace of free ammonia.
- The sample viscosity is too high for effective film formation and entrainment.
- Sample integrity: Emphasizes preserving representative sample composition while removing gas inclusions; the method should not chemically alter the product.
- Laboratory implementation: Defines requirements for sample preparation, assessment of sample suitability, and when alternative de-aeration techniques should be considered. (Specific apparatus dimensions and operational parameters are contained in the standard text.)
Applications and users
Who benefits from EN ISO 10248:
- Fertilizer manufacturers conducting routine quality control of liquid and suspension fertilizers.
- Analytical and QA/QC laboratories preparing samples for physical property testing (density, viscosity, settling behavior).
- Agricultural product certifiers and conformity assessment bodies requiring standardized sample preparation methods.
- R&D teams developing new suspension formulations who need consistent de-aeration for comparative testing.
Practical uses:
- Ensures consistent test results by removing bias introduced by entrained air.
- Reduces variability in measurement of physical properties important for product performance and handling.
- Helps determine whether a sample requires alternative preparation due to ammonia content or high viscosity.
Related standards
- ISO 10248:1996 - original ISO document referenced by EN ISO 10248:1999.
- EN adoption indicates harmonization within CEN member states for laboratory practice in fertilizer testing.
Keywords: EN ISO 10248, fluid fertilizers, de-aeration, suspension samples, film disentrainment, fertilizer testing, sample preparation, CEN, ISO 10248.