How does the ALERT PRO 1000 work?
The World’s First Real-Time Airborne Asbestos Warning Device
ALERT PRO 1000’s patented design analyses the airborne fibres within the environment in real-time and then utilises both laser-light and scattering technology, the paramagnetic properties of asbestos and a unique algorithm to make a statistical analysis of the fibres within the air to a 99% confidence.
The air is drawn in a controlled manner through the ALERT PRO 1000 inlet ~50ml/min at up to 600 particles per second through a pair of laser beams and a magnetic field.
The resulting ‘ALERT’ instrument can detect airborne asbestos in minutes or even seconds (depending on fibre concentration) rather than days. It has been tested extensively in field locations involving commercial, public, and domestic buildings where asbestos clearance work (so far involving crocidolite, amosite and chrysotile asbestos forms) has been undertaken.
Spatial Light Scattering
When a particle is illuminated with a beam of light in ALERT’s optical chamber it scatters the light in a pattern dependent on its size, shape and structure. These patterns are like a thumbprint and are recorded and used to ascertain whether the particle is fibrous or not.
Asbestos fibres produce distinctive scattering patterns, however the light scattering technique is not enough on its own to differentiate the difference between highly dangerous asbestos fibres and less hazardous fibres of glass or gypsum commonly found.
All fibrous particles are preferentially aligned vertically by ALERT’s airflow and the system measures the angle of the alignment sit enters and then moves between the two laser beams.
The paramagnetic properties of all asbestos fibres mean that when they are exposed to a magnetic field asbestos fibres will try to align themselves. This change in alignment is measured by ALERT’s algorithm enabling a distinction of asbestos fibres from other non-asbestos fibres passing through the optical chamber.
By providing a real-time airborne assessment the ALERT enables safe works to continue uninterrupted by providing reassurance that the activity being undertaken isn’t disturbing asbestos containing materials (which may or may not have been previously identified) within a structure and un-intentionally releasing asbestos fibres.
The images below illustrate ALERT’s dual beam asbestos warning system and the forwarded scattered light which is focused and recorded twice – once before and once after exposure to a magnetic field.
*DISCLAIMER: There are certain types of man-made fibres such as steel or magnetically engineered fibres that may have similar magnetic properties to those of asbestos and could therefore be wrongly assessed as asbestos. However unlike asbestos such fibres are not normally found in the ambient airborne environment where building, renovation or demolition work is being undertaken.