ISO 8178-2:2021

Overview

ISO 8178-2:2021 specifies measurement and evaluation methods for gaseous and particulate exhaust emissions from reciprocating internal combustion engines (RIC engines) tested in the field. It covers discrete-mode steady-state tests (Clause 4) for single operating points or weighted cycle-based tests, and in-service performance assessment using portable emission measurement systems (PEMS) (Clause 5). This third edition updates field-testing requirements and expands PEMS and moving-average-window evaluation methods.

Key Topics and Requirements

• Scope of application: Non‑road machinery, industrial equipment, marine installations, generating sets, diesel rail traction and similar fielded engines.
• Discrete-mode steady‑state testing (Clause 4): Procedures for preparing the engine, installing sampling probes, specifying test conditions (intake/exhaust, cooling, fuels, lubricants) and conducting weighted or single-point emissions tests in the field.
• In‑service testing with PEMS (Clause 5): Requirements for continuous and combined data sampling, ECU data streams, data pre‑processing, working‑event determination and moving average window evaluation for typical in‑service operation.
• Measurement equipment & calibration: Guidance on gaseous analysers (including Zirconium Dioxide NO analysers), particulate sampling and dilution, exhaust flow, torque and speed measurement, and data accuracy requirements.
• Data handling & calculations: Procedures for emissions evaluation, transient data processing, handling temporary signal loss, and reporting instantaneous measured and calculated data files.
• Normative annexes (A–K): Detailed PEMS specifications, test procedures, data pre‑processing algorithms, working‑event algorithms, proxy power determination, gaseous emissions calculations, ECU torque conformity, and calibration/performance specs for key instruments.

Practical Applications

• Field verification of engine emissions performance and compliance testing.
• In‑service monitoring of fleets, off‑road equipment, marine and rail engines for regulatory and environmental reporting.
• Commissioning, troubleshooting and durability checks where laboratory testing is impractical.
• Research, development and validation of after‑treatment systems under real-world conditions.

Who Uses This Standard

• Engine and equipment manufacturers conducting field certification and development testing.
• Independent test laboratories and certification bodies performing on‑site compliance checks.
• Fleet operators, environmental agencies and regulators auditing in‑service emissions.
• R&D teams and OEM service organizations needing robust procedures for PEMS-based assessments.

Related Standards

• ISO 8178 series (other parts) and related ISO/TC 70 guidance on internal combustion engine emissions. For full cross-references and annex details consult the ISO 8178-2:2021 publication on the ISO website.

Keywords: ISO 8178-2:2021, exhaust emission measurement, PEMS, reciprocating internal combustion engines, field testing, gaseous and particulate emissions.