Air Monitoring Technology Reader

Pinssar Air Monitoring Technology Reader

The Pinssar Air Monitoring Technology Reader is an LLSP (Laser Light Scattering Photometery) instrument developed to specifically address some limitations of existing LLSP instruments. Pinssar provides continual monitoring of DPM – diesel particulates in underground environments. Primarily these limitations centred on maintenance concerns, elimination of non-diesel particles and providing data to end users in an easily understandable format.

Instruments in underground mining and tunnelling environments are subjected to extremes of temperature, humidity, vibration, water and dust ingress.

Conventional LLSP instruments designed for either laboratory or field use are typically made with a plastic body, have  small disposable filters to provide clean air to the optics, use particle size impactors to remove large particles and are either 240V or battery powered.


The maintenance needs of these instruments can be considerable, and are dependent on the nature of the environment where they are used.

Dirtier environments require more frequent maintenance.  Clean air filters for the optical cell are typically replaced at monthly intervals or on an operating hour basis.

Particle size impactors collect oversize material on an impaction plate, allowing finer particles to pass.

During the course of sampling, oversize material accumulates on the plate to the point where the material either dislodges and enters the instrument, alters the size fraction passing or blocks the inlet to further particles.

Particle size impactors require the removal of oversize collected deposits at least weekly to prevent contamination of the cell.

The Pinssar Reader is housed in a water and dust resistant stainless steel enclosure, fitted with ruggedised power and communications connections suitable for permanent use underground.  It uses a 2 stage sintered metal and borosilicate glass fibre filtration assembly to significantly extend the time between filter cleaning to 6 months or beyond depending on sampling rates.

The Pinssar Reader uses size selective sampling inlet to collect only particles with a size of 800nm or less.

Particles this size are primarily generated from engine exhaust emissions.  The inlet is designed with a shroud to prevent large particles from entering the Reader.

This effectively prevents non-diesel particles from entering the Pinssar Reader, keeping the instruments response similar to the calibration aerosol.  This also results in a lower accumulation of particles in the oversize trap of the cyclone, considerably reducing the frequency required to remove oversize collected deposits.

Humidity can affect LLSP measurements, particularly where high humidity levels can result in condensation of water droplets or altering the properties of particles.  Air sampled by the Pinssar Reader is heated to 60 degrees Celsius prior to entering the optical cell.  This ensures a relative humidity of less than 60% is maintained in the optical cell, minimizing errors potentially arising from extraneous water.

To account for possible long-term drift, from progressive deterioration in laser power output, detector sensitivity or particle contamination over time, following every measurement, a sample of filtered particle free air (99.99% removal of particles down to 0.01μm), is first flushed through the Reader and then a zero reading is taken.  This value is subtracted from the sample reading to derive a true instrument response.  Additionally, eight instrument parameters are measured and recorded with the instrument response to ensure the quality of measurement is maintained.

The Pinssar Reader is factory calibrated against a known diesel emission source.  This ensures the response of the Reader is specifically calculated to diesel particles.


Particles generated from older technology diesel engines differ substantially from newer technology diesel engines.

To account for this, the Pinssar Ambient Air Monitoring System (AAMS) software accompanying the Reader has functionality whereby users can add a site-specific calibration factor to account for variations in their diesel particulate mix.

The AAMS software was specifically designed to display a simple dashboard approach for end users of the data with standard charting capabilities.

The software has flexibility in setting action limits and the ability to map the locations of the devices.

Whilst relatively simple in look, the AAMS software is capable of communicating with multiple Readers simultaneously, providing notification of instrument status, error codes as well as notification to end users.

The Pinssar Reader is capable of being installed into a variety of communication networks, having on-board capability for a multitude of communication protocols.