EN 1237:1995 PDF

Overview

EN 1237:1995 (adopting ISO 5311:1992, modified) is a CEN standard that specifies procedures for determining the bulk density (tapped) of solid fertilizers (excluding powder fertilizers). The standard defines how to compact a known volume of fertilizer by tapping and calculate tapped bulk density as mass per unit volume (g/cm3). It is not suitable for materials that contain more than 20% by mass of particles larger than 5 mm in diameter. Two complementary methods are covered: a machine‑tapping method and a hand‑tapping method.

Key topics and technical requirements

• Scope and limits
  • Applies to dry solid fertilizers; powders and materials with excessive coarse particles (>5 mm, >20% by mass) are excluded.
  • Method 2 (hand tapping) is limited to spherical granules and prills, not sharp‑edged grains.
• Sample preparation
  • Test samples must be prepared according to ISO 7742 and ISO 8358 (sample reduction and preparation).
• Test methods
  • Method 1 - Machine tapping
    • Pour fertilizer through a funnel into a specified measuring cylinder, then tap using a tapping machine (specified camshaft frequency ~250 min‑1).
    • Typical procedure: controlled discharge time, use of a plastic collar, tap 2 500 times, remove surplus and weigh.
  • Method 2 - Hand tapping
    • Manual filling and tapping of the measuring cylinder (gentle taps during discharge, final drops/raises), scraping excess and weighing.
    • Specific procedural steps include discharge time control and light hand tapping (2–3 taps/s), with final 2 mm–3 mm lifts/drops.
• Measurement and expression
  • Bulk density (tapped) = mass of test portion (g) / volume of measuring cylinder (cm3).
  • Repeatability: difference between two successive determinations by the same operator should not exceed 0.01 g/cm3.
• Test report requirements
  • Include sample identification, method used, numerical result and units, any unusual observations and any deviations or optional operations.

Applications and users

• Useful for fertilizer manufacturers, QC/analytical laboratories, packaging and logistics planners, storage managers and regulators.
• Practical uses:
  • Designing packaging and storage capacity (silos, bags, bulk containers).
  • Calculating expected volume for bulk shipments and stock management.
  • Quality control to ensure consistent physical properties and handling behaviour.
  • Regulatory compliance and specification reporting.

Related standards

• ISO 5311:1992 (base international method) - referenced/modified
• ISO 3944:1992 - determination of bulk density (loose)
• ISO 7742:1988 - sample reduction for solid fertilizers
• ISO 8358:1991 - preparation of samples for analysis

Keywords: EN 1237:1995, ISO 5311:1992, bulk density tapped, fertilizer testing, tapped bulk density, fertilizer quality control, packaging design, storage density.