ISO 15715-2003 PDF

Full title and description

St ISO 15715-2003 — Binders for paints and varnishes — Determination of turbidity. This International Standard specifies an instrumental method for measuring the turbidity (loss of transparency) of clear liquids used as binders and related coating materials, applicable to resins, resin solutions, solvents, clear coating materials, monomers and other liquids where clarity is a specified property.

Abstract

ISO 15715:2003 defines a laboratory procedure using a turbidimeter to quantify the turbidity of clear coating-related liquids. Measurements are reported in nephelometric units referenced to formazin (now commonly expressed in formazin nephelometric units, FNU). The standard covers instrument requirements, calibration, sample handling, measurement cell specifications, reporting of results and limitations due to colour, bubbles or particulate types that may interfere with light-scattering measurements.

General information

• Status: Withdrawn (superseded).
• Publication date: March 2003.
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 87.060.20 (Binders for paints and varnishes).
• Edition / version: Edition 1 (2003) — national adoption sometimes cited as St ISO 15715-2003.
• Number of pages: 6 pages.

Scope

The standard applies to objective instrumental determination of turbidity in clear liquids used in coating formulations and binder raw materials where transparency or clarity is specified. It is intended for quality control, incoming inspection and R&D tasks where detection of haze, colloidal matter or undissolved solids in resins, solvents, monomers and clear coating components is required. The method is not intended for highly coloured or strongly absorbing samples without appropriate mitigation (e.g., use of near-infrared measurement conventions) and notes conditions where interferences may affect accuracy.

Key topics and requirements

• Measurement principle — nephelometric measurement of light scattered at a defined angle to quantify turbidity; results referenced to formazin-based calibration and reported in nephelometric units (FNU where modernized).
• Instrument specifications — optical geometry, recommended measurement angle, light source wavelength/bandwidth and detector requirements to ensure repeatability and comparability.
• Calibration and standards — use of formazin reference suspensions or commercially traceable calibration standards; calibration frequency and procedures.
• Sample handling and preparation — recommended procedures to avoid bubbles, ensure representative sampling and definition of acceptable sample cells (optical path length and centring).
• Reporting — required reporting content (result units, instrument identification, calibration status, sample identification, any deviations and measurement uncertainties or repeatability information).
• Interferences and limitations — effect of dissolved colour, strongly absorbing substances, pigments (e.g., carbon black), air bubbles and temperature; guidance to reduce or account for these influences.
• Precision and comparability — recommended practices to achieve reproducible results and references to related turbidity precision documents.

Typical use and users

This test method is typically used by quality control laboratories in paint, varnish and binder manufacturing, incoming‑goods inspection teams, formulation R&D groups, independent testing laboratories and instrument manufacturers/calibration services. Its primary uses are acceptance testing of raw materials and clear formulations, detection of haze or contamination, stability checks and specification verification where clarity is a contractual requirement.

Related standards

Standards commonly referenced alongside ISO 15715:2003 include ISO 7027 (turbidity measurement methods and precision), ISO 4618 (paints and varnishes — vocabulary), and various ISO and EN test methods for binders and coating raw materials (for example standards covering viscosity, colour and other binder properties). ISO 15715:2003 has been superseded by a later revision published as ISO 15715:2025, which updates measurement conventions and reporting (including modern use of FNU and detailed instrument specifications).

Keywords

turbidity, binders for paints and varnishes, turbidimeter, formazin, FNU, clear liquids, resins, solvents, monomers, quality control, ISO 15715:2003, turbidity determination

FAQ

Q: What is this standard?

A: ISO 15715:2003 is an International Standard that specifies an instrumental method for determining the turbidity of clear liquids used in paints, varnishes and binder materials.

Q: What does it cover?

A: It covers measurement principle and instrument requirements, calibration to formazin references, sample handling and measurement cells, reporting of results, and discussion of interferences and limitations affecting turbidity determinations.

Q: Who typically uses it?

A: Paint and varnish manufacturers, binder suppliers, QC and R&D laboratories, testing and calibration laboratories, and instrument manufacturers use the method for acceptance testing, incoming inspection and formulation checks.

Q: Is it current or superseded?

A: ISO 15715:2003 has been withdrawn and superseded by a newer edition published as ISO 15715:2025. The 2003 edition should be treated as withdrawn; users are advised to adopt the 2025 revision for current requirements and measurement conventions.

Q: Is it part of a series?

A: The standard is part of the body of ISO documents maintained by ISO/TC 35 (Paints and varnishes) relating to test methods for binders and coating materials, and it is often used together with related standards such as ISO 7027 (turbidity) and ISO 4618 (paints vocabulary).

Q: What are the key keywords?

A: Key keywords include turbidity, binders for paints and varnishes, turbidimeter, formazin, FNU, clear liquids, resins, solvents and quality control.