Editing Emerging technologies, emerging markets – fostering the innovation potential of research infrastructures

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Absorption photometers (or aethalometers) are devices that determine the light absorption coefficient of aerosols through the measurement of transmissivity of a filter that is gradually loaded with particles (Arnot et al. 2005). They usually employ light sources at several wavelengths from the UV to near IR. Most of the available commercial instruments use systems for automatic change of the filter when transmissivity is below a critical level, while some of them measure also the backscattered light in order to compensate the final measurement for this effect. Some instruments provide directly the value of the equivalent black carbon (in gram per cubic meter) that would produce this absorption, through the assumption of a specific absorption coefficient per unit mass.  
 
Absorption photometers (or aethalometers) are devices that determine the light absorption coefficient of aerosols through the measurement of transmissivity of a filter that is gradually loaded with particles (Arnot et al. 2005). They usually employ light sources at several wavelengths from the UV to near IR. Most of the available commercial instruments use systems for automatic change of the filter when transmissivity is below a critical level, while some of them measure also the backscattered light in order to compensate the final measurement for this effect. Some instruments provide directly the value of the equivalent black carbon (in gram per cubic meter) that would produce this absorption, through the assumption of a specific absorption coefficient per unit mass.  
  
<div class="tablecaption" id="table24">TABLE 24 STRENGTHS AND LIMITATIONS OF ABSORPTION PHOTOMETERS/AETHALOMETERS</div>
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TABLE24STRENGTHSANDLIMITATIONSOFABSORPTIONPHOTOMETERS/AETHALOMETERS  
{| class="wikitable"
 
! scope="row" | Strengths
 
! scope="row" | Limitations
 
|-
 
! scope="row" | No calibration required as the measurement is relative to a blank filter
 
| The conversion to equivalent black carbon concentration depends critically from the assumed specific absorption coefficient
 
|-
 
! scope="row" | Multiple wavelength
 
| High flux volumes or long integration times are required to measure low concentrations
 
|-
 
! scope="row" |
 
| Need filter change
 
|-
 
! scope="row" |
 
| Corrections are required to take into account the filter/loading effects
 
|}
 
Producers are presented in table 25.
 
  
<div class="tablecaption" id="table"></div>
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TABLE 25 COMPANIES PRODUCING ABSORPTION PHOTOMETERS/AETHALOMETERS
{| class="wikitable"
 
! scope="row" | Producer name
 
! scope="row" | Website
 
|-
 
! scope="row" | Magee Scientific
 
| https://www.mageesci.com/
 
|-
 
! scope="row" | AethLabs
 
| https://www.aethlabs.com
 
|-
 
! scope="row" | ThermoFisher Scientific
 
| https://www.thermofisher.com
 
|}
 
  
 
=====2.2.2.2.3 Nephelometers=====
 
=====2.2.2.2.3 Nephelometers=====

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