When using DSTech products, please consult the support materials linked here for operating instructions, troubleshooting procedures, data acquisition software, and general guidance on AQ monitoring.
Our team is here to support your AQ application - we are deeply committed to ensuring our customers' success. Please contact us below for technical support, calibration/maintenance services, and consultations on your project.
What is black carbon?
Black carbon (BC) is the light absorbing component of particulate matter (PM) pollution emitted by biomass and fossil fuel combustion. Common sources include wood heaters, internal combustion engines, and wildfires. Prolonged exposure to these combustion emissions increases the incidence of respiratory diseases and other adverse health impacts. Black carbon is also a short-lived but powerful climate forcer in the atmosphere: Only carbon dioxide contributes more to global radiative forcing. Monitoring and mitigating black carbon pollution is critical to protecting human health and the environment.
Why measure black carbon? Don't we care about particulate matter?
Particulate matter (PM) is an umbrella term for all solid or liquid particles suspended in the atmosphere. PM is generated by both natural processes, such as the suspension of fine sand or sea salt, and anthropogenic sources, such as internal combustion engines. PM even forms directly in the atmosphere through secondary mechanisms, such as the nucleation of volatile organic compounds released by plants. Often, studies focus on measuring the total mass of PM suspended in a unit volume of air, as this is an important air quality indicator. However, it is diffcult to pinpoint the contribution of relevant anthropogenic sources using these PM mass concentration data alone, since there are many other unrelated sources captured within the same measurement.
Why monitor gaseous pollutants + black carbon together?
When measured alone, black carbon and gaseous pollutant concentrations are important air quality indicators that reveal potential impacts on the surrounding environment. By measuring all these pollutants simultaneously in an integrated package, we can more effectively detect and characterize local pollution sources that drive air quality trends. For example, an ObservAir can be outfitted to measure BC, carbon monoxide (CO), and nitrogen dioxide (NO2). If high BC and CO concentrations are detected simultaneously, this could be an indication of nearby biomass combustion, while elevated BC and NO2 concentrations may point towards diesel engine emissions. Without all three pollution measurements, it would not be possible to make this distinction. Although these type of deductions are not universal (since they typically depend on the sampling context), the simultaneous measurement of BC and gaseous pollutants paints a more complete picture of local air quality to enable the characterization major air pollution drivers.
How often should I change the ObservAir filter? Why?
To determine BC concentrations, the ObservAir measures the optical absorption of particulate matter collected on the disposable filter tab. As the sensor draws in polluted air, light absorbing BC accumulates on the filter, and the intensity of light transmitted through the filter dims predictably over time. For example, if the ObservAir is drawing 100 ccm of air and the light signal dims by 10% over 1-minute, this correlates to an average BC concentration of 5 ug/m3 (not actual figures). However, if the light intensity dims too much, this mathematical relationship deteriorates, and the BC signal degrades (BC concentration measurements are lower than they should be). Therefore, the filter must be replaced periodically to maintain BC measurement performance.
How long does the ObservAir battery last?
The ObservAir battery will last about 24 hours at a sample flow rate setting of 100 ccm. Higher flow rates diminish battery life, while lower flow rates extend it.
Why is your logo a moth? What does it mean?
Our logo represents the peppered moth and it's evolution in response to air pollution. Prior to the Industrial Revolution, peppered moths in England had white wings with black or gray spots, so as to camouflage against the local trees' light bark and lichens. During the 19th century, the area around Manchester became blanketed in air pollution from the coal-powered textile mills and factories that proliferated. As this sooty (black carbon) pollution deposited on the trees, they gradually grew darker. White moths now stood out against the dark bark, clearly visible to predators, and so darker moths naturally evolved in response. Our logo shows the dark wing of the peppered moth turning back to its natural, lighter color, as we hope our work eliminates the air pollution that drove this evolutionary response.