ISO 12141:2002

Overview

ISO 12141:2002 - "Stationary source emissions - Determination of mass concentration of particulate matter (dust) at low concentrations - Manual gravimetric method" - is a reference method for measuring low dust concentrations in ducted gas streams. The standard addresses concentrations below 50 mg/m³ (standard conditions) with particular validation around 5 mg/m³, and was developed and validated for waste incinerator emissions. It defines manual gravimetric sampling using pre‑weighed filters, drying and re‑weighing, and accounts for upstream deposits and sampling blanks to determine particulate mass concentration.

Key topics and technical requirements

• Sampling principle: extraction of a representative integrated sample with isokinetic control, capture on a pre‑weighed plane filter, drying and re‑weighing to obtain mass increase.
• Low‑level sensitivity: achieved by rigorous weighing procedures, extended sampling times, or high‑volume sampling (nozzle diameters typically 20–50 mm; flowrates ~5–50 m³/h).
• Isokinetic sampling: nozzle inlet velocity should match duct gas velocity to avoid particle bias; velocity ratio characterizes deviation from isokinetic conditions.
• Sampling plane & points: located in a straight section of duct (recommended ≥5 hydraulic diameters upstream, ≥2 downstream); local flow angle <15°, no reverse flow, velocity ratio (max/min) <3:1.
• In‑stack vs out‑stack filtration: standard covers both; filtration temperature and location affect measurements when gases contain unstable, reactive or semi‑volatile substances.
• Quality control: pre/post weighing, overall blank tests (overall blank should not exceed 10% of daily regulatory limit), weighing control parts, and validation rule that collected dust must be ≥5× positive overall blank to accept a series.
• Performance and reporting: procedures for calculating nozzle diameter, flowrates, weighing bias, uncertainty, and required test report content.

Applications and users

ISO 12141:2002 is practical for:

• Emission testing in waste incinerators, power plants, and other stationary sources where low particulate concentrations are expected.
• Environmental laboratories performing manual gravimetric stack tests.
• Stack testing contractors and plant operators conducting compliance monitoring or performance verification.
• Calibration and validation of automated monitoring systems (AMSs) when manual reference measurements are required.
• Regulatory agencies specifying or reviewing low‑level particulate measurement methods.

Keywords: ISO 12141:2002, particulate matter, gravimetric method, stationary source emissions, low concentrations, isokinetic sampling, high‑volume sampling, waste incinerator emissions.

Related standards

• ISO 9096:1992 - Manual gravimetric method for higher concentrations
• EN 13284‑1 - European standard closely aligned with ISO 12141
• ISO 10780, ISO 3966 - flow and velocity measurement methods referenced by ISO 12141
• ISO 10155 - guidance for calibration of automated monitoring systems