HD 478.2.6 S1:1993

Overview

HD 478.2.6 S1:1993 - adopted as SIST HD 478.2.6 S1:2002 - is a CLC classification standard that addresses environmental conditions appearing in nature caused by earthquake vibration and shock. It is part 2 of a series on classification of environmental conditions and sits within the environmental testing domain (ICS 19.040). The standard provides a consistent framework to describe, classify and communicate seismic vibration and shock effects for use in product specification, testing and design.

Key topics

The standard focuses on classification and characterization rather than prescriptive design values. Key technical topics and typical requirements covered include:

• Scope and definitions - clear terminology for earthquake-related vibration, shock, and associated environmental influences.
• Classification scheme - hierarchical categories to describe severity and type of seismic vibration and shock for different environments and applications.
• Parameters for characterization - descriptive parameters used to quantify seismic events (for example: amplitude, duration, frequency content, shock pulses) presented as classification attributes rather than fixed test levels.
• Measurement and reporting guidance - recommendations on how to measure, record and report earthquake-induced vibrations and shocks to ensure reproducible communication between suppliers, manufacturers and test laboratories.
• Application notes - guidance on how to interpret classifications for product testing, installation, mounting and transport considerations.
• Documentation and labeling - standardized ways to specify seismic environmental conditions in technical documentation and procurement specifications.

Note: HD 478.2.6 S1 is a classification document; it defines how to describe environmental conditions rather than prescribing specific test procedures or numerical thresholds.

Applications

This standard is useful wherever seismic vibration and shock need to be specified, assessed or communicated:

• Product designers and mechanical engineers - for assessing robustness and selecting components in seismically active regions.
• Environmental and reliability test laboratories - to classify test conditions and to prepare test reports that align with industry terminology.
• Manufacturers and suppliers - for creating product specifications and installation instructions that reference standard seismic classes.
• Certification bodies and procurement teams - to ensure consistent requirements are applied in contracts and conformity assessments.
• Infrastructure planners and installers - for specifying mounting, anchoring and mitigation measures in seismic zones.

Related standards

HD 478.2.6 S1 complements other environmental testing and seismic standards by providing a classification framework. Users typically consult this document alongside test-method standards and regional seismic codes to translate classification into specific test programs.

Keywords: HD 478.2.6 S1:1993, SIST HD 478.2.6, classification of environmental conditions, earthquake vibration and shock, environmental testing, seismic vibration, seismic shock, CLC standard.