Table 1.
Reference methods,a equivalent methodsb and minimum requirements for portable, direct-reading instruments for the measurement of pollutants as per RSECE.9
| Pollutant | Reference method | Equivalent method | Technical Characteristics |
|
|---|---|---|---|---|
| Maximum allowable errorc | Resolution | |||
| Carbon dioxide (CO2) | Non-dispersive infrared (NDIR) | Electrochemical method; infrared (FTIRd), PAS – photo acoustic sensor | Maximum reference concentration ± 10% | 1 ppm |
| Carbon monoxide (CO) | Non-dispersive infrared (NDIR) | Electrochemical method; infrared (FTIR), PAS – photo acoustic sensor | Maximum reference concentration ± 10% | 0.1 ppm |
| Particulate matter (PM10) | Gravimetric method with size-selective sampling heads PM10 (filter collection and weighing) | Optical dispersion (UV; Laser); absorption of beta radiation; tapered element oscillating microbalance (TEOM); piezoelectrioc resonance | Maximum reference concentration ± 10% | 1 mg/m3 |
| Formaldehyde (HCHO) | Sample collection and chromatography analysis (ISO 16000-2:2006, ISO 16000-3:2001 and ISO 16000-4:2004) | Passive samplers impregnated with DNPHe diffusive sampling method; electrochemical method; impinger method; photometry method | Maximum reference concentration ± 20% | 0.01 ppm |
| Total volatile organic compounds (TVOC) | Sample collection and chromatographic analysis (ISO 16000 – Part V:2007, Part VI:2004) | Passive samplers (Tenax, activated carbon, etc.); canisters; FID – flame ionization detector; PID – photo ionization detector; PAS – photo acoustic sensor; infrared (FTIR) | Maximum reference concentration ± 10% | 0.01 ppm |
a The reference method is the method set by national, European (EU) or international regulations (e.g., ISO) for the measurement of a specific air pollutant. CEN methods CEN (EN-ISO) are considered reference methods.
b The equivalent method is a measurement method that provides an adequate result when compared to those obtained through the reference method; the difference in the results obtained through the two types of methods is within a certain interval of statistical uncertainty.
c The maximum allowable error is the maximum measurement error when compared to a reference value set by specifications or regulations (the latter corresponds to the maximum reference concentration set by RSECE), regarding a measurement, measurement instrument or measurement system. (ISO/IEC Guide 99-12:2007 International Vocabulary of Metrology – Basic and General Concepts and Associated Terms, VIM).
d Fourier transform infra-red.
e Dinitrophenylhydrazine (DNPH) absorbent solution.