Continuous Emissions Monitoring (CEMS) and IECEx/ATEX Stack Gas Detectors in Australia

Continuous Emissions Monitoring Systems (CEMS) are vital tools for Australian industrial facilities to ensure compliance with air quality regulations. By continuously measuring key stack gases, CEMS help operations (mining sites, power stations, refineries, etc.) stay within permitted emission limits. For example, Western Australia’s regulator notes that environmental licences may require CEMS on large sources, with a code specifying acceptable methods and performanc. Reliable CEMS data not only keep facilities compliant but also protect worker and community health by preventing unreported pollutant releases.

Key components of an extractive CEMS typically include:

• Sample probe & pump: Extracts gas from the stack and pulls it through the system

• Sample line: Tubing that carries the flue gas to the analyzers

• Gas analyzers: Measure concentrations of target pollutants in the sample

• Filters: Remove dust/particulates that could damage sensors

• Gas conditioning: Removes moisture or other interferents from the sample

• Calibration system: Injects reference gases to maintain accuracy

• Data acquisition system (DAHS): Collects, stores and processes the measurement data for reporting

Each component must meet strict specifications (e.g. US EPA or AS/NZS standards) to ensure data validity. A CEMS provides real-time monitoring and alerts, so operators can quickly identify any exceedance of emission limit. The data are typically fed into a DAHS (Data Acquisition and Handling System) that logs time-stamped gas concentrations and flow rates. These records satisfy reporting requirements under Australian legislation (e.g. State EPAs or the national NEPM framework).

Regulated Pollutants and Standards in Australia

Australian air quality regulations and permits focus on key stack pollutants. In particular, sulfur dioxide (SO₂) and nitrogen oxides (NOx, i.e. NO + NO₂) are routinely monitored. For example, Western Australia’s CEMS Code explicitly includes SO₂ and NOx as common monitored species. National ambient air guidelines (NEPM) also set limits for NOx and SO₂ to protect public health. Other typical CEMS measurements include carbon monoxide (CO), hydrogen sulfide (H₂S) or total reduced sulfur, oxygen (O₂), carbon dioxide (CO₂), as well as ancillary parameters like stack opacity/dust, flow rate and temperature. Across industries, these parameters are tracked to ensure all criteria pollutants stay within the facility’s licence limits.

Regulatory bodies in each state enforce these standards. For instance, a coal-fired power plant in New South Wales or Queensland must install CEMS to continuously verify its SO₂/NOx emissions against the limits set by the EPA or Department of Environment. In general, any stationary source (boilers, furnaces, process vents) that could significantly impact air quality is likely to have CEMS requirements as part of its environmental approval.

IECEx/ATEX Certified Ex-Sampling Gas Detector

To perform on-site emissions tests (e.g. audit of stack gases or spot-checks), engineers often use portable ex-sampling gas detectors. Apexio Industrial’s SKY3000 detector is an example of a rugged, multi-gas instrument tailored for stack sampling in hazardous environments. This handheld unit has an internal pump and can connect to a telescopic probe or sampling tube, allowing operators to draw flue gas into the sensors. It can simultaneously detect SO₂, NO and NO₂ (three key combustion gases) with electrochemical sensors.

Importantly for Australian sites, the SKY3000 is fully IECEx and ATEX certified for use in explosive atmospheres. IECEx/ATEX approval means the device’s design (intrinsic safety “ia”, flameproof enclosure “Ex d”, etc.) meets international standards for Zone 1 and Zone 2 hazardous areas. In practice, this ensures the detector can safely operate in environments with flammable gases or dust (common in mining, petroleum and chemical plants). The unit’s robust metal housing and industrial-grade internals let it withstand harsh field conditions – moisture, dust, vibration and temperature swings – without compromising safety or performance apexioindustrial.com.au.

Key features of this ex-sampling detector include:

• Multi-Gas Measurement: Simultaneous real-time readings of SO₂, NO and NO₂, with graphical display of concentration, TWA, STEL and peak values.

• IECEx/ATEX Certification: Explosion-proof design compliant with IEC 60079 standards (intrinsic safety Ex ia, flameproof Ex d, etc.), allowing legal use in gas zones 1 and 2

• Rugged Portability: Flameproof “da” enclosure, intrinsically safe sensors and filters to handle extreme industrial atmospheres (oil/gas, petrochemical, marine, etc.)

• Extended Sampling Capability: Optional telescopic probe and up to 20 m of sample tubing enable access to high or confined stack outlets.

• Data Logging & Connectivity: Onboard data logger records all gas readings and calibration events. Bluetooth/USB output allows real-time data transfer to mobile devices or PC software for compliance reporting.

These capabilities make the detector a versatile mobile CEMS probe – ideal for periodic stack tests, commissioning, or as a portable backup to fixed CEMS analyzers.

Applications Across Australian Industry

Apexio’s ex-sampling gas detector is applicable wherever emissions must be checked. In power generation, coal and gas-fired plants rely on continuous monitoring of SO₂ and NOx; a portable device lets engineers spot-check stacks or validate the installed CEMS. In the oil & gas and petrochemical sectors (refineries, LPG plants, offshore platforms), regulations similarly demand monitoring of toxic gases; the unit’s IECEx certification makes it perfectly suited for hazardous processing areas. Mining operations often involve combustion engines and furnaces that emit NO₂ and SO₂. Even though coal mine ventilation is typically monitored for methane, mining powerhouses and smelters use CEMS to control air pollutants. In all these industries – from steelworks to chemical plants to waste-to-energy facilities – engineers use portable gas detectors to verify emissions during maintenance, troubleshooting or regulatory audits.

For Australian engineers, the combination of explosive-atmosphere safety and accurate pollutant sensing is critical. The SKY3000 detector is explicitly built for the challenging sites found in oil & gas, petrochemical and marine industries, and its ruggedness equally benefits coal power stations and large mines. By bridging fixed CEMS and handheld monitors, it helps operators maintain environmental compliance across diverse settings.

Data Recording and Compliance Reporting

Regulations require not only measurement but also record-keeping of emissions data. As noted in guidance documents, a DAHS “can collect, store and analyse” CEMS data. In practice, the portable detector fulfills this role by internally logging all sensor readings with timestamps. After a stack survey, engineers can download the logged data to generate emission reports or verify compliance. This digital record – often including calibration and bump-test history – is essential for audits by environmental agencies.

By using an IECEx/ATEX-certified detector, Australian facilities ensure both safety and accuracy in their emission monitoring programs. Continuous monitoring with CEMS and spot-checks with portable devices together give a complete picture of stack gas concentrations. In summary, investing in quality gas detection (sensors, probes, data systems) is the surest way for mine, power station and plant engineers to meet Australia’s strict emissions standards while protecting people and the environment