Introduction
Professionals may choose to apply a Span value for a specific project, area, and/or aerosol, using gravimetric analysis as their source of input.
This method may be used to increase the degree of accuracy of Ranger|Dust's concentration readings.
This is because the manufacturer calibrates these instruments using ISO 12103 Test Dust. Aerosols encountered in the field--having different optical properties from the Test Dust--will all give different readings.
Tools
Parts
No parts specified.
Video Overview
How to apply a custom calibration to Ranger | Dust
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Attach a PMX sensor head to Ranger and turn it on
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Enter the Settings menu by pressing and holding the LEFT ARROW
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Select the Calibrate submenu
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Select the Span Calibration menu
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Verify that the Span is set to 1.000 for all channels.
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Aeroqual recommends the use of a gravimetric sampling setup as your reference
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Simultaneously begin and end the sampling periods of both Ranger|Dust and your chosen reference
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Once your co-location sampling is completed, calculate the average mass concentration of your reference. This becomes PMref
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Next, calculate the average mass concentration of Ranger|Dust. This becomes PMranger
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Calculate the ratio of the PMref over PMranger. This becomes your Span
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Enter Settings and navigate to Calibrate>Span Calibration
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On the relevant channel, adjust the Span as the Span from the previous step
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Exit the Settings menu by pressing and holding the LEFT ARROW
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If you have applied a Span to some channels, but not others, you may notice the concentration readings for a smaller fraction channel exceeds the concentration readings of a larger fraction channel. For example, PM2.5 > TSP.
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If you remove the PMX sensor head from any Ranger base, and attach it to a different Ranger base, the Span will be retained
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Your PMX sensor head will now give readings that account for a specific project, area, or aerosol.
Your PMX sensor head will now give readings that account for a specific project, area, or aerosol.