SCAQMD’s AQ-SPEC program aims at being the testing center for low cost air monitoring sensors to establish performance standards by which sensors are evaluated.  The program evaluates sensors in both controlled laboratory conditions and in the field. In the field, sensors are tested alongside one or more of SCAQMD’s existing air monitoring stations using traditional federal reference or equivalence methods to gauge overall performance. Sensors demonstrating acceptable performance in the field are then brought to the AQ-SPEC laboratory for more detailed testing in an atmospheric chamber under controlled conditions.  

Summary Tables & Reports


 PM Sensors

Type Pollutant(s) Approx.
Cost (USD)
 microaeth AethLabs (microAeth) Optical BC
(Black Carbon) 
~$6,500  R~ 0.79 to 0.94  
 aqev1 Air Quality Egg
(Version 1)
Optical  PM  ~$200  R2 ~ 0.0    
 aqev2pm Air Quality Egg
(Version 2) 
Optical PM  ~$240 PM2.5: R2 ~ 0.79 to 0.85
PM10: R2 ~ 0.31 to 0.40
 alphasenseopcn2 Alphasense
Optical  PM1.0, PM2.5 & PM10  ~$450  PM1.0: R2 ~ 0.63 to 0.82
PM2.5: R2 ~ 0.38 to 0.80
PM10: R2 ~ 0.41 to 0.60
R2 ~ 0.99  
(1,291 KB) 
 dylosdc1100 Dylos
Optical  PM(0.5-2.5)  ~$300  R2 ~ 0.65 to 0.85 R2 ~ 0.89 PDF
(1,384 KB) 
 foobot  Foobot Optical  PM2.5  ~$200    R2 ~ 0.55    
 airbeam HabitatMap
Optical  PM2.5  ~$200  R2 ~ 0.65 to 0.70 R2 ~ 0.87   PDF 
(1,144 KB) 
  hanvon1 Hanvon
  (Hanvon N1)
Optical  PM2.5  ~$200 R2 ~ 0.52 to 0.79    
  metonenm  MetOne (Neighborhood Monitor) Optical PM2.5  ~$1,900 R2 ~ 0.53 to 0.67     
 airnut  Moji China 
Optical PM2.5   ~$150   R2 ~ 0.81 to 0.88     
 partector Naneos
Electrical PM
(LDSA: Lung-Deposited Surface Area) 
~$7,000 PM1.0: R2 ~ 0.1
PM2.5: R2 ~ 0.2
 laseregg       Origins      (Laser Egg) Optical  PM2.5 & PM10    ~$200 PM2.5: R2 ~ 0.58
PM10: R2 ~ 0.0
 perkinelmerelm  Perkin Elmer
Optical PM  ~$5,200  R2 ~ 0.0    
 purpleair  PurpleAir
Optical PM1.0, PM2.5 & PM10  ~$150   PM1.0: R2 ~ 0.93 to 0.95
PM2.5: R2 ~ 0.77 to 0.92
PM10: R2 ~ 0.32 to 0.44
R2 ~ 0.95
R2 ~ 0.99
R2 ~ 0.97
(1,072 KB) 
 purpleair-ii  PurpleAir
 Optical PM1.0, PM2.5 & PM10    ~$200   PM1.0: R2 ~ 0.96 to 0.98
PM2.5: R2 ~ 0.93 to 0.97
PM10: R2 ~ 0.66 to 0.70
R2 ~ 0.99
R2 ~ 0.99
R2 ~ 0.95
(1,328 KB) 
 rtimicropem RTI
Optical  PM2.5  ~$2,000  R2 ~ 0.65 to 0.90 R2 ~ 0.99  PDF 
(1,087 KB)
 shinyeipmevalkit  Shinyei
(PM Evaluation Kit)
Optical  PM2.5  ~$1,000  R2 ~ 0.80 to 0.90 R2 ~ 0.93   PDF
(1,156 KB) 
 speck  Speck  Optical  PM2.5  ~$150 R2 ~ 0.32    
 tsiairassure  TSI
Optical  PM2.5  ~$1,500  R2 ~ 0.82    


Gaseous Sensors

Type Pollutant(s)  Approx.
Cost (USD)
 Summary Report
  2bpom  2B Technologies (POM)  UV absorption
(FEM Method)
O3   ~$4,500 R2 ~ 1.00   R2 ~ 0.99   PDF 
(1,295 KB)
 aeroqual  Aeroqual
Metal Oxide  O ~$500  R2 ~ 0.85   R2 ~ 0.99   PDF
(1,197 KB) 
 aqev1cono2o3  Air Quality Egg
(Version 1)
Metal Oxide  CO, NO2 & O3  ~$200  CO: R2 ~ 0.0
NO2: R2 ~ 0.40
O3: R2 ~ 0.85 
 aqev2cono2 Air Quality Egg
(Version 2) 
Electrochem   CO & NO2 ~$240   CO: R2 ~ 0.0
NO2: R2 ~ 0.0
  AQE   Air Quality Egg
(Version 2)
 Electrochem O3 & SO2  ~$240   O3:
R2 ~ 0.0 to 0.20
SO2: R2 n/a
 aqmeshv3 AQMesh
Electrochem  CO, NO, NO2
& O3 
 ~$10,000 CO:
R2 ~ 0.42 to 0.80
R2 ~ 0.0 to 0.44
R2 ~ 0.0 to 0.46
R2 ~ 0.46 to 0.83 
 perkinelmerelm Perkin Elmer
Metal Oxide  NO, NO2 & O3  ~$5,200  NO: R2 n/a 
NO2: R2 ~ 0.0
R2 ~ 0.89 to 0.96
 smartcitizenkit   Smart Citizen Kit Metal Oxide  CO, NO ~$200  CO:
R2 ~ 0.50 to 0.85
NO2: R2 ~0.0 
 specsensors   Spec Sensors Electrochem  CO, NO2 & O3  ~$500  CO:
R2 ~ 0.84 to 0.90
R2 ~ 0.0 to 0.16
R2 ~ 0.0 to 0.24 
 sensit UNITEC
 Metal Oxide CO, NO2 & O ~$2,200  CO:
R2 ~ 0.33 to 0.43
R2 ~ 0.60 to 0.65
R2 ~ 0.72 to 0.83 
R2 ~ 0.99
R2 0.82 to 0.90  
(1,283 KB) 
(1,177 KB)

*The correlation coefficient (R2) is a statistical parameter indicating how well the performance of each sensor compares to that of a Federal Reference Method (FRM), Federal Equivalent Method (FEM), or Best Available Technology (BAT) instrument.  An R2 approaching the value of 1 reflects a near perfect agreement, whereas a value of 0 indicates a complete lack of correlation.  All R2 values reported in these tables are based either on a 5-min or 1-hr average data. The Lab R2 values are also based on the average ambient conditions (20 degrees C and 40% RH) experiment in the chamber. An ad-hoc rating system will be developed to summarize the overall performance of these sensors.


All documents, reports, data, and other information provided on this website are for informational use only. The majority of sensors evaluated as part of the Air Quality-Sensor Performance Evaluation Center (AQ-SPEC) program were field-tested inside a custom-made aluminum enclosure to protect the sensors from windblown rain, harsh sunlight, and animals. The field evaluations reports included on this website contain data collected at our monitoring station during a specific 30- to 60-day period and may not be duplicated at the same or different location, season, time period, or weather conditions (e.g. temperature, relative humidity, pressure, wind speed/direction). As the overall sensor performance may be affected by the specific environmental conditions experienced at our location during the time of testing, replication and/or duplication may not possible to achieve. The laboratory evaluation was conducted in the AQ-SPEC’s environmental chamber with simulated pollutant and interferent concentrations that were generated from nebulizer solutions, dust dispensers, and gas dilution calibrators. Generated environments may not be able to fully replicate the conditions that may be experienced under ambient settings. The sensor assembly, installation, and use can also impact the reliability of the products evaluated by the AQ-SPEC program. South Coast Air Quality Management District (SCAQMD) makes no claim, warranty, or guarantee that these devices will or will not work when operated by other users for their specific applications.

The South Coast AQMD AQ-SPEC program in the Quality Assurance division of the Science and Technology Advancement office aims at providing information to and for the benefit of the public to make informed purchasing decisions on commercially available “low cost” air quality sensor devices. In accordance with this mission, the general policy of the Board of the Agency is to exclude from the AQ-SPEC website all commercial advertising and promotional material, including links which provide exclusive private or financial benefit to commercial, non-public enterprises and which do not promote or enhance a public benefit to the general public. As a government agency, the SCAQMD neither endorses nor supports individual private commercial enterprises through display of their products on the AQ-SPEC website or through providing links to the sites of such commercial enterprises.

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