Osiris Portable Dust Monitor

Turnkey Instruments

design and manufacture a range of

easy to use instruments which continuously measure and

record the concentration of airborne particles. In their

environmental mode these instruments can simultaneously

monitor the concentrations of TSP, PM10, PM2.5 and PM1

particles. Alternatively, in their workplace mode, the

inhalable, thoracic and respirable fractions can be monitored.

These instruments are sensitive to airborne particle

concentrations down a fraction of a microgram per cubic

metre.As such they easily meet the sensitivity requirements

of the new European Directives and the DETR guidelines for

PM10 and PM2.5 and will meet future requirements for PM1

particles.

An internal reference filter can be used to confirm

the gravimetric calibration of the instruments.

All instruments feature internal data logging for the particle

concentrations. Osiris and Topas also allow wind speed and

direction and two external gas or noise meter inputs to be

recorded at the same time. Traffic counting inputs can be

provided.

All instruments use our own proprietary nephelometer. A

pump continuously draws an air sample through the

nephelometer which analyses the individual particles as they

pass through a laser beam. These same particles are then

collected on the reference filter. The nephelometer's

dedicated microprocessor can analyse individual particles

even if there are millions of them per litre. This allows size

fractions to be determined at concentrations up to several

mg/m3. Above this there is an indicator range which can be

used without sizing up to 60 mg/m3.