The Air XD Dust Monitor from Trolex uses optical particle counting (OPC) technology to dynamically count and size airborne respirable dusts in real time. This has many advantages over conventional monitoring techniques, which typically only give total exposure over a fixed monitoring period after that exposure has occurred. 

The key benefit for process monitoring is that because the data is time-stamped and has a very high temporal resolution (down to 10 seconds), it can be used to link raised levels of respirable dusts to a particular activity or process. 

The Air XD Dust Monitor was used by this customer to enable them to monitor the milling process, in turn helping them identify losses from the process that can be corrected, whilst reducing overall exposure for their workers. They have multiple vertical mills with increasingly fine respirable crystalline silica (RCS) dust produced at different levels of the mills.  

What was the Air XD used for? 

The examples given in this report highlight two areas where the customer was able to gather valuable data about their processes using the Air XD Dust Monitor. 

The first is an example of a process improvement/correction highlighted by the data provided by the Air XD and the second shows the benefits to occupational health monitoring of real-time data. 

The examples shown on the case study show particulate matter (PM) readings gathered alongside the silica milling process during a 24-hour period. Plots show data for PM10, PM4.25, PM2.5 and PM1. 

These refer to respirable dusts with diameters in different size bands. PM10 is equivalent to the dust that would be captured by a 10 µm filter in gravimetric sampling, PM4.25 a 4.25 µm filter and so on. 

Two examples were used. One showing the benefit of real-time dust monitoring data for the milling process, and another showing the benefits of real-time dust monitoring vs conventional post-exposure monitoring.