Workshop on “Comparability of measurements of NO, CO, and SO2 at low ambient level”

Project Description

Measurements of NO, CO, and SO2 at ambient concentration levels have become an important issue to carry out based on legislation and the public concern. The European Council set the legislation for the measurement requirements of the pollutants including the data quality objectives for the measurements. To help the task of the member state the European standardization body (CEN) prepared the measurement standards for the measurement method for each of the gas compounds.

One of the important requirements for the measurement is the traceability of the measurements to the national standards. This also means that to meet the requirements the national responsible authorities must have capabilities to provide a calibration service at the concentration levels needed for the measurements.

A workshop will be held to illustrate the state of the art for the preparation of the gas concentrations for calibration purposes by the use of the dilution methods of the gas standards. The workshop will concentrate both on the static injection method and the dynamic dilution method. Participants from the expert laboratories and from the NMIs will share their experience and the best practice for the use of both methods.

One of the outcomes of the workshop will be a decision on the need to organize the comparison exercise.

The nominal concentration of the gases of interest lie within the ranges:

Nitrogen monoxide in air50 10-9 – 750 10-9 mol/mol
Carbon monoxide in air2 10-6 – 15 10-6 mol/mol
Sulphur dioxide in air25 10-9 – 200 10-9 mol/mol