Dust Monitoring

Contact us for more details on how we can assist you in effevctively monitoring dust emissions as there are a wide range of sampling and detection methods available, some of which are indicated below:

1. Automatic real-time point analyser methods

Provide high-resolution measurements (typically hourly or shorter time periods).  In order to ensure that data is accurate and reliable, there needs to be a high standard of maintenance, calibration and QA/QC procedures in place.  These types of monitors can measure different particulate fractions such as PM10 and PM2.5 when fitted with designated inlet heads.  Monitors such as TEOM or beta-attenuation analysers (with heated inlets) need to be corrected by a factor of 1.3, when comparing results based on a gravimetric standard.

2. Gravimetric monitoring

This monitoring method is considered to be the most accurate and produces concentrations equivalent to the EU reference samplers, which are used to set EU limit values.  Such systems have designated inlet heads to measure different particulate fractions and a typical measurement is taken over 24 hours.  The measurement system is time-consuming as filters need to be individually weighed and accurate filter weighing and conditioning facilities are required.  This method cannot be used as a trigger system as it does not produce instantaneous readings.

3. Remote optical/long path analysers

These are relatively low-cost automatic analysers that have been developed specifically for portable or personal exposure applications.  These tend to be battery or mains powered and use the light scattering principle to measure PM10 and other particulate fractions.

4. Hand-held monitors

Although these types of monitors are not as accurate as automatic monitors and cannot be used for long term studies, they are ideal for walk-over surveys of construction sites as they provide real time or instantaneous dust readings (every second).  Such monitors can be set up to measure different particle sizes and can be used to assess short term peaks and breaches of set limits.

In measures 3 and 4, a factor is used to convert the measured number of particles in each size range to an overall mass concentration – which may not be accurate without a gravimetric filter backup.

In addition to the individual monitors, other site infrastructure is often required.  This particularly refers to automatic monitors and can include equipment housing, air-conditioning or heating systems, electrical systems, telephone lines or modems and air sample inlet systems.

Automatic monitoring equipment should have had some independent verification of performance, further information on this and siting requirements and equipment suppliers is available from DEAT

5. Dust assessment

Approaches to measure the amount of dust deposited on a surface tend to focus on either determining the soiling of a surface by a change in its properties or determining the quantity of dust deposited, by weight.  These techniques are often used to determine nuisance and may be requested by a client or an enforcing authority in cases of complaint from sensitive receptors.

Accepted methodologies include:

Deposit gauges: These are simple, but accurate methods to measure nuisance dust. Dust is collected onto a horizontally mounted capture container, or in the case of a Directional Dust Gauge, into four vertical tubes aligned in different directions.  The dust collected can also be analysed to determine its composition.

Soiling Rate Measurement: This is used to determine changes in the soiling rates of surface over a period of time.  The most popular method is the Sticky Pad system to measure the soiling on a white adhesive surface over a known period.  This provides a measurement of the deposition (as percentage Effective Area Coverage per day) using a reflectometer.  Alternatively, glass slides can be used which is exposed for a week before returning to the lab to measure changes in reflectance.  Results are measured in soiling units (su) per week, whereby 20 su/week reflects a dusty activity.