ISO 10349-11:1992

Overview

ISO 10349-11:1992 is an international standard developed by the International Organization for Standardization (ISO) that specifies a precise test method for determining the specific gravity (relative density) of solutions used in photographic processing. This standard is part 11 of the ISO 10349 series on photographic-grade chemicals test methods, providing a reliable procedure to measure the density of photographic chemicals to ensure quality and consistency in photographic applications.

The method detailed in ISO 10349-11 involves the use of a calibrated hydrometer and a constant-temperature water bath set at 25 °C. By reaching thermal equilibrium, the standard ensures accurate and reproducible results critical in photographic chemistry.

Key Topics

• Specific Gravity Measurement
  The standard outlines the determination of specific gravity as the ratio of the density of photographic solutions to that of water under controlled temperature conditions.

• Apparatus Requirements

  • Hydrometer: A displacement calibrated hydrometer capable of measuring density with precision up to 0.001 units, calibrated at or corrected for 25 °C.
  • Hydrometer Cylinder: A transparent glass cylinder approximately 250 ml in capacity, tall enough to accommodate the hydrometer floating freely.
  • Constant-Temperature Water Bath: Maintains a stable temperature of 25 °C ± 0.05 °C to ensure thermal equilibrium during measurement.

• Procedure Details
  The test requires pouring 100 ml of the photographic solution into the hydrometer cylinder, submerging it in the water bath, and allowing the sample to stabilize. The specific gravity is then read at the meniscus level on the hydrometer scale.

• Data Reporting
  Test reports should specify the method used, all relevant operating details including any deviations, and full identification of the tested sample to support traceability and reproducibility.

• Temperature Correction Notes
  Where hydrometers calibrated at 15.6 °C are used, a conversion factor is provided to reference all results to the standard 25 °C measurement temperature.

Applications

ISO 10349-11:1992 is essential for industries and laboratories involved in:

• Photographic Chemical Manufacturing
  Ensuring batch-to-batch consistency of chemical solutions such as developers, fixers, and other processing chemicals through specific gravity checks.

• Quality Control and Assurance
  Routine testing during production and formulation to verify concentration and purity of photographic chemicals, impacting overall photographic quality.

• Research and Development
  Accurate density measurements assist in formulation adjustments and stability studies for new photographic chemical products.

• Educational and Testing Laboratories
  Providing a standardized method for students and professionals to practice and validate photographic chemical properties.

Related Standards

ISO 10349-11:1992 is part of a comprehensive series addressing various test methods for photographic-grade chemicals. Relevant complementary standards include:

• ISO 10349-1: General Test Methods for Photographic Chemicals
  Establishes the foundational safety and procedural guidelines applicable across all parts.

• ISO 10349-2 to ISO 10349-10
  Cover specific chemical quality parameters like insoluble matter content, heavy metals, halide content, alkalinity, volatile matter, and more, supporting comprehensive chemical characterization.

• ISO 10349-12: Determination of Density
  Provides additional guidance on density measurements complementing the specific gravity test.

By implementing ISO 10349-11:1992, photographic chemical manufacturers and laboratories can achieve precise density measurements, ensuring chemical performance and contributing to high-quality photographic processing outcomes. This standard supports consistent product quality, safety compliance, and advancement in photographic chemistry technology.