PCME - Passionate about Particulate

ProScatter™ Backscatter is a PCME laser back scatter technique which provides a reliable alternative to traditional opacity instruments for monitoring both abatement plant failure and particulate concentrations in the Metals, Minerals and Chemical Industries plus Power/Boiler and Combustion Applications.

Core features of the technology are:

• Resolves dust levels to below 10mg/m³ enabling installations in applications with emissions well below the resolution limit of traditional Opacity instruments
• An optical path which can be completely uniquely checked by the automatic insertion of a scattering body ensuring the automatic span check is a true challenge of the instrument’s functionality and contamination condition
• High reliability by having no moving parts in the receiver path and using optical components which do not age with temperature.
   

The sensor measures the amount of light scattered back from particles in the stack illuminated by a modulated laser. Stray scattering from the far inside stack wall is eliminated by a critically controlled “telescopic” detector field of view and the low angle of measurement increases the effective penetration of the measurement volume into the stack (typically half way across). Instrument response is proportional to dust concentration for a given particle type and size and may be calibrated in mg/m³ by comparison to the results of a standard reference test (isokinetic test).

• Low angle of measurement increases the effective penetration of the measurement volume into the stack (typically half way across) compared to higher angle back scatter instruments which provide very small measurement volumes.
• Any stray scattered light from the stack wall which would be the source of an instrument offset is eliminated by a “field of view” which is optimised to measure well into the stack while being insensitive to signal from the far stack wall.
• Effects of ambient light are eliminated using a modulated laser source
• Optical components are maintained clean by the use of an air purge which protects the optical surfaces from making direct contact with stack gas or particulate.
• Conveniently mounted on one side of the stack and requires no light absorber or beam dump on the opposite site of the stack.
• Non-intrusive sensor enables critical optical components to be kept contamination free by simple air purging (instrument air or blower option)
• Convenient hinged enclosure permits ease of access to the optical surfaces for cleaning if required.
   

PCME ProScatter™ Backscatter technology includes an automatic zero and span check. A scattering body is automatically rotated into the laser path and the resultant scattered light signal is measured by the detector.

• Any deterioration caused by laser ageing, instrument drift or optics contamination is detected automatically, in effect providing both a span and contamination check result.
• Manual audit capability via a set of independent reference materials as part of periodic functionality and linearity tests.