Measuring emissions in hazardous areas

A large industrial site, which can potentially have many leak sources, is a typically hazardous area demanding a tough, reliable analyser for gas emission monitoring.


ATEX is the term used for two European directives controlling these high-risk, explosive atmospheres. One concerns the protection of workers, while the other focuses on equipment and protective systems. In Britain, the requirements of the former are put into effect by the Dangerous Substances and Explosive Atmospheres Regulations 2002 (DSEAR).  Employers must classify their potentially hazardous areas into zones (see below) and all equipment and protective systems intended to be used in those areas must meet certain requirements.

The Procal solution

Among the recently approved systems is the Procal 2000, which can now continue monitoring hydrocarbons, nitrogen oxide, nitrogen dioxide and other gases  in the chemical and refining industries, where it is already being used.

The Procal 2000 is a Continuous Emission Monitoring Process Infra-Red Analyser, which uses the reflective beam principle to directly measure process gas as it enters an in-situ sample cell.  Installation is simple and requires very little maintenance.  This makes it suitable for marine environments too.

Its advanced design is the result of many years of research and development in the field of stack gas analysis.

Fire hazards

Under ATEX, gases and vapours are grouped in three zones, each indicating the likelihood and probable duration of hazards being present in flammable concentrations.  Beginning with the most severe, these are numbered 0 (where a flammable atmosphere may be present continuously), 1 and 2.

Each piece of equipment used in these areas has marked on it a series of letters and numbers, which indicate its protection qualities. The Procal 2000 is marked ATEX II 2 G Ex d IIB T4/T6 (application dependent).  This means that it is flameproof and can be safely used in zones 1 and 2 (which would include chemical plants, LNG terminals and a number of mining operations) and where gases such as methane, ethylene and hydrogen (which is especially flammable) are present.

Among other certifications, the Procal 2000 is approved by the IEC, the International Electrotechnical Commission, which is responsible for worldwide standards for electrical, electronic and related technologies.

The challenge of measuring emissions in hazardous areas is often compounded by climatic extremes. A range of accessories ensures that the Procal 2000 can stand up to these. For example, a head cooler allows operation when outside temperatures are high, and a gas flow bypass ensures operation when temperature fluctuations cause thermal stress in a structure.

To find out more about our analysers and their approvals, contact us or call us on 01733 232 495.