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Opacimeter: dust monitor for industrial emissions

Published on 18 October, 2023

Industrial production processes,

Particulate matter emission monitoring is a crucial part of environmental management in industry, helping to ensure that environmental regulations are complied with and the impact of emissions is minimised. Among the variety of dust monitors available, opacimeters play a key role in measuring the opacity and concentration of exhaust gases in industrial facilities.

What means opacity?

Opacity, in the context of emissions and air quality, refers to the amount of light that is blocked or scattered by the presence of particles or pollutants in a gas stream.

Its measurement is used as a way to assess the concentration and density of airborne solid particles such as soot, dust or ash particles.

The measurement of opacity and particle concentration is a very common technique in industrial emission monitoring and control and in applications where it is important to assess and control the particles released into the air.

It is also an essential tool for verifying compliance with emission regulations.

In Spain, opacity monitoring of particulate emissions in industry is regulated by Law 34/2007, of 15 November, on Air Quality and Atmospheric Protection.

How does a dust monitor work?

An industrial opacimeter is an instrument used to measure the opacity and particulate concentration of exhaust gases.

These instruments use optical systems: when the gas stream passes through a beam of light, airborne particles in the air can block or scatter the light, reducing the amount of light that reaches the other side and thus determining the amount of particulate matter present.

Opacimeters are typically installed in stacks and exhaust ducts of emission sources for on-site sampling, at the outlet of emission control equipment (e.g. baghouses, industrial dryers or electrostatic precipitators) and in areas where airborne dust is present, such as storage areas, transport areas, milling areas, etc.

Which industries use opacimeters as real-time dust monitoring equipment?

Dust monitors are very useful in any industry where there is a need to monitor and control the particulate matter present in the exhaust gas stream, usually associated with industrial combustion processes.

Some examples are:

  • Power generation plants
  • Chemical industry
  • Cement plants
  • Metallurgical industry
  • Paper industry
  • Food industry
  • Waste incineration plants

Dust monitors for ATEX explosive atmospheres

The vast majority of industries where particulate emissions are generated are classified as ATEX (explosive) atmospheres, where there is a risk of explosion due to the presence of flammable substances in the form of gas, vapour, mist or dust in suspension.

When selecting a suitable dust monitor it is important to choose one that complies with ATEX regulations and is designed for use in potentially explosive atmospheres and the specific environmental conditions of the area, such as temperature, humidity and pressure, as some of these environments can be extreme and the monitor must be able to withstand these conditions.

Here is our selection of dust monitors.

In addition, proper maintenance and regular calibration of the opacimeter is essential to ensure its correct and reliable operation.

At Envira, we have large experience of working in these types of ATEX atmospheres and our technicians are highly qualified to carry out the installation, commissioning and maintenance of ATEX monitoring equipment, ensuring personnel safety and business continuity.

Do you want to know more about Envira?

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