PCME - Passionate about Particulate

The PCME QAL 181 is an approved Particulate Continuous Emission Monitor (CEM) providing high quality emission measurement for low dust concentrations from industrial processes, especially in Incineration, Power Plant and Cement Kiln applications. The instrument provides a proven solution for applications where CEN standards EN 14181 / EN 13284-2 are applied (plant falling under the Waste Incineration and Large Combustion Plant EU Directives). The instrument holds QAL1 approval as specified in EN 15267-3, under both MCERTS and TUV, in addition to compliance with US EPA standard PS-11 for PM-CEMs.

PCME's patented ProScatter™ Forward Scatter technique measures the light from a laser source scattered by particles in a near-forward direction and results in an improved signal to noise ratio compared to other techniques, with excellent resolution and zero drift characteristics. This allows for high stability even at low concentrations (< 0.1 mg/m³) as well as rugged operation in stacks where emissions exceed 100 mg/m³.

PCME QAL 181 advantages include:

• Reliable and rugged design, proven for long term operation at elevated temperatures and with minimised instrument maintenance
• System self-checks, with logging of Zero and Span check data for QAL3 reporting
• QAL Reporter PC software option to provide secure and powerful emissions reporting and automated QAL3 reporting in full compliance with EN 13284-2
• Entry and Standard control units with advanced graphics and user interface screens, features including alarming, graphical trending, data logging, 4-20mA output
• PLUS control unit option for sensor networking (up to 16 sensor channels) via industry standard Modbus, multiple inputs for external devices (e.g. for Temp and O₂ normalisation)

The PCME QAL 181 supersedes the LMS181, an instrument currently proven in many applications worldwide.

Resolution and Sensitivity

The PCME QAL 181 uses a low-angle forward light scattering measurement principle unique to PCME (see ProScatter™ Forward Scatter). The measured cone of scattered light is larger than normal for light scatter instruments, which provides:

• Excellent sensing resolution and sensitivity, due to an increased signal-to-noise ratio
• Reduced cross-sensitivity to changing particle size, allowing a greater range of applications for which the instrument is suitable

Inherently Reliable Design

Using tough high-grade components and enclosures, and designed to overcome problems encountered with alternative light scatter technologies, the PCME QAL 181 offers outstanding reliability:

• No optical fibres, which are prone to degradation in elevated temperatures
• No moving active measurement parts, ensuring sensing components remain correctly aligned. Alternative technologies require movement of the position-critical detectors for the performance of self checks. The PCME QAL 181 avoids this by introducing a diffuser into the light path, which gives the additional benefit of a true check of the instruments ability to measure scattered light, rather than just attenuated light

Audit Tools & QAL3 Reporting

As an approved Particulate Measurement System for compliance monitoring, the PCME QAL 181 has fully automated self checks (Zero and Span) with a dedicated audit channel for QA data logging. This enables a simplified process for operators to meet QAL3 standards, with the option of PCME's QAL Reporter PC software for automated QAL3 reporting in full compliance with EN 13284-2.

In addition to automatic self checks, the PCME QAL 181 offers a manual audit unit providing ultimate quality assurance, enabling a further layer of auditing for measurement and system integrity. The Proscatter™ 5-point Filter audit unit facilitates a comprehensive system check via a 5 point linearity check.

Process Conditions

The PCME QAL 181 is suitable for: 

• After bagfilter, cyclone and electrostatic precipitator arrestment plant
• Non-condensing / dry flue gases*
• Both constant and variable flue gas velocities
• Corrosive flue gases (corrosion protection option)
• Variable particulate size
• Explosive atmosphere zones 2 and 21

* For wet / condensing flue gas applications see PCME STACK 181 WS

Typical Applications

The PCME QAL 181 is used to monitor emissions from the following types of processes:

• Municipal Waste and chemical Incinerators
• Cement Kilns
• Coal fired power stations
• Gas/Oil fired power stations
• Refinery boilers
• Biomass power plant
• Chemical, Mineral and Metal plant with highly abated emissions (eg after bagfilter)

The PCME QAL 181 is capable of monitoring the very low levels of particulate associated with particulate contamination and clean work environments as well as the more substantial dust levels associated with explosive dust levels, eg:

• Automatic control of air extraction plant based on ambient dust levels
• Personal dust exposure monitoring
• Contamination control
• Tunnel monitoring
• LEL and HEL explosive dust level monitoring

Performance