Overview
ISO 15011-3:2009 specifies a laboratory method to measure the ozone emission rate during arc welding using a hood technique. The standard is aimed primarily at gas‑shielded arc welding but can be applied to other processes (for example, self‑shielded flux‑cored arc welding) when welding is performed automatically under the hood. ISO 15011-3:2009 is part of the ISO 15011 series on health and safety in welding and allied processes and supports assessment of fume and gas generation for occupational health evaluation.
Key topics and requirements
- Test principle: Perform automatic arc welding inside a continuously extracted hood; measure ozone concentration at a fixed sampling point and multiply by hood air flow rate to obtain the ozone emission rate (concentration × flow = emission rate).
- Hood setup: Semi‑enclosed “hood” type test chamber with the sampling point 1 000 mm above the base; interior non‑reflecting.
- Air flow control: Extraction adjusted to an air flow of 2 m³/min (±5% measurement accuracy recommended); air flow measured by calibrated anemometer, differential flow meter, or equivalent device with logging capability.
- Ozone measurement: Calibrated chemiluminescence ozone meter (or equivalent) capable of measuring up to 10 ml/m³ and connected to a digital logger with ≤1 s logging interval.
- Sampling system: PTFE or stainless steel sampling line (≤10 mm internal diameter), PTFE filter close to sampling point to prevent fume ingress.
- Supporting measurements: Instruments for current, arc voltage, wire feed speed, shielding gas flow, and CTWD/ETWD setting devices; all calibrations traceable to national standards.
- Procedures and reporting: Trial tests, controlled welding parameters, documented test report and calculation of average stable ozone concentration per the annexed procedures.
Practical applications and users
ISO 15011-3:2009 is used by:
- Occupational health and safety professionals assessing relative ozone generation from welding processes and consumables.
- Welding product manufacturers (consumables, wires, shielding gases) evaluating emissions under controlled conditions.
- Research laboratories studying how welding parameters, shielding gas, and base material affect ozone formation.
- Regulatory and standards bodies comparing emission tendencies between processes or products.
Note: emission rate data help predict relative changes in workplace exposure and to identify control measures; they do not provide absolute exposure predictions or directly determine ventilation requirements.
Related standards
Keywords: ISO 15011-3:2009, ozone emission rate, arc welding, hood technique, welding fume sampling, chemiluminescence ozone meter, gas‑shielded arc welding, occupational health.