ISO TR 7553-1987 PDF

Full title and description

Fertilizers — Sampling — Minimum mass of increment to be taken to be representative of the total sampling unit. This technical report gives guidance on the minimum mass of a single increment (sub‑sample) that should be taken when treating the entire sampling unit so that the reduced mass remains representative of the whole.

Abstract

The report specifies the extent of mass reduction of a sample beyond which the error in representativity can no longer be ignored and provides criteria for the minimum mass of an increment to ensure that analytical results remain representative of the sampling unit. It is intended to support consistent sampling practice for fertilizers and to reduce sampling-induced bias and variability.

General information

• Status: Published.
• Publication date: July 1987 (Edition 1).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 65.080 (Fertilizers).
• Edition / version: Edition 1, 1987.
• Number of pages: 7.

Core bibliographic and lifecycle information from the ISO bibliographic entry.

Scope

This technical report applies to sampling procedures for fertilizers and provides guidance on the minimum mass of an individual increment (or sub‑sample) to be taken when the whole sampling unit is treated or reduced. The scope covers solid fertilizer materials where representativity of reduced samples is critical for reliable laboratory analysis; it does not prescribe analytical methods but focuses on sampling mass limits and their effect on representativity.

Key topics and requirements

• Definition and justification of a minimum increment (sub‑sample) mass required to maintain representativity of the sampling unit.
• Guidance on the extent of mass reduction and the point beyond which reduction introduces unacceptable representativity error.
• Considerations for different particle sizes and types of solid fertilizers when selecting increment mass.
• Practical recommendations to support subsequent sample reduction and analysis (complementary to sample‑reduction standards).
• Emphasis on minimizing sampling‑induced variability and bias in analytical results.

These topics are intended to be used together with other sample‑reduction and fertilizer sampling standards to form a complete sampling workflow.

Typical use and users

Used by quality control laboratories, fertilizer manufacturers, testing and inspection bodies, agricultural laboratories, standards committees, and regulatory authorities involved in fertilizer production, certification and trade. It is applied when designing sampling plans, reducing bulk samples before analysis, and preparing standard operating procedures to ensure representative analytical samples.

Related standards

Commonly referenced alongside ISO and industry standards on sample reduction and fertilizer testing, for example ISO 7742 (Solid fertilizers — Reduction of samples) and other ISO/TC 134 publications addressing sampling and test methods for fertilizers and soil conditioners. National adoptions and translations are available from various national standards bodies.

Keywords

fertilizers; sampling; sample increment; minimum mass; representativity; sample reduction; ISO TR 7553; quality control.

FAQ

Q: What is this standard?

A: ISO/TR 7553:1987 is an ISO technical report that gives guidance on the minimum mass of a single increment (sub‑sample) to be taken so that the mass remaining after reduction is still representative of the total sampling unit for fertilizers.

Q: What does it cover?

A: It covers criteria and guidance for minimum increment mass and acceptable mass reduction limits to avoid introducing significant representativity errors when sampling solid fertilizers. It does not specify laboratory analytical methods.

Q: Who typically uses it?

A: Quality control and testing laboratories, fertilizer manufacturers, inspection bodies, regulators, and standards committees involved in sampling and sample preparation for fertilizer analysis.

Q: Is it current or superseded?

A: The document is published as ISO/TR 7553:1987 (Edition 1). Users should check for any later revisions, related ISO standards, or national adoptions that may update sampling and sample‑reduction practices; related standards such as ISO 7742 (1988) address sample reduction methods that are commonly used alongside this report.

Q: Is it part of a series?

A: It is part of the body of ISO work under ISO/TC 134 (Fertilizers, soil conditioners and beneficial substances) and is intended to be used in conjunction with other ISO standards on fertilizer sampling and sample reduction rather than as a standalone series.

Q: What are the key keywords?

A: Fertilizers, sampling, sample increment, minimum mass, representativity, sample reduction, quality control.