Direct reading dust monitors are useful in applications that include industrial hygiene surveys, occupational exposures, construction sites, and environmental monitoring. Many of the dust monitors break down the dust using size selectors for various respirable fractions such as PM1, PM2.5, respirable and PM10.
Dust monitor equipment calibration services are critical. Most monitors currently on the U.S. market function as optical particle counters: The dust particles interact with a light beam generated by a source, the interaction generates scattered light that is received by the detector and transformed by an algorithm into corrected data such as mass concentration. The mass concentration reading is not the direct measurement of the mass of dust—it is the product of a mathematical algorithm from an indirect measurement. These monitors are a challenge in that many manufacturers use different optical sensors and algorithms to measure dust concentration.
The mass concentration data generated from dust monitors manufactured by different companies, when compared to one another, can be off as much as 400 percent. Compared to gravimeric analysis, the gold standard, some are closer than others. Often times the dust used for calibration is a surrogate for the intended dust being measured? These monitors most often are used for ball park estimates or alarms and should not take the place of media sampling when used with carcinogenic or highly toxic dusts. Many of the units include or offer Bluetooth, data logging, touchscreens, extended concentration ranges, and user friendly interfaces.
Why calibrate your dust monitor?
- Our A2LA ISO 17025 accredited lab offers comparison to the gold standard for the calibration of dust concentration using state of the art dust generation lab and gravimetric analysis.
- Technicians conduct a thorough cleaning and inspection to ensure clean optics, good-working mechanical factors and proper flow rate prior to calibration.
- The units are then subjected to an Arizona Road Dust test (ISO 21103-1, A1) and compared against a gravimetric filter, simultaneously subjected to the same test dust, and weighed.