ISO 5011:2020

Overview

ISO 5011:2020 - "Inlet air cleaning equipment for internal combustion engines and compressors - Performance testing" defines uniform laboratory test procedures, conditions, equipment and reporting formats to allow direct comparison of air cleaners. The standard targets core performance characteristics: air flow restriction / differential pressure, dust collection efficiency, dust capacity, and oil carry‑over (for oil bath air cleaners). It applies to air cleaners used on internal combustion engines and compressors in automotive and industrial applications.

Key topics and technical requirements

ISO 5011:2020 specifies test methods, measurement accuracy and standard conditions and covers:

• Test materials and conditions

  • Use and preparation of test dust (e.g., Arizona test dust per ISO 12103-1)
  • Test oil specification for oil bath air cleaners
  • Requirements for absolute filter media and validation of absolute filter efficiency
  • Temperature and humidity control during tests

• Performance tests (automotive and industrial)

  • Restriction and differential pressure versus airflow
  • Initial and full‑life efficiency tests (Absolute filter method and Direct weighing method)
  • Dust capacity tests and presentation of capacity results
  • Variable airflow and filter element pressure collapse tests (where applicable)
  • Specific procedures for scavenged air cleaners, precleaners, and secondary elements

• Oil bath air cleaner tests

  • Oil carry‑over measurement
  • Full‑life efficiency, capacity and recovery tests

• Measurement, reporting and annexes

  • Measurement accuracy, corrections to standard conditions (Annex G)
  • Test equipment guidance (Annex B) and report sheet templates (Annex C/D)
  • New additions in the 2020 edition such as validation procedures and Annex H (Penetration sensitivity)

Practical applications and who uses this standard

ISO 5011 is used by:

• Air filter and precleaner manufacturers to validate and certify product performance.
• Automotive and engine OEMs for selecting inlet air cleaning systems that meet engine protection and performance targets.
• Industrial compressor manufacturers and fleet operators to ensure air intake reliability in harsh environments.
• Independent test laboratories performing standardized comparative testing and reporting.
• Procurement and maintenance teams who specify performance requirements (restriction, efficiency, capacity, oil carry‑over) for replacement filters.

Benefits include improved comparability of products, clearer performance claims, better engine protection, and optimized service intervals.

Related standards

• ISO 12103-1: Test contaminants for filter evaluation (Arizona test dust)
• ISO 5167-1: Measurement of fluid flow by differential pressure devices (referenced for flow measurement)