Technology

Limit of detection

Typical range

Reference/Note

Chemiluminescence

NO2 detector based on reaction between Luminol and NO2 in air

10 ppt

65ppt - 18 ppb

Fast response ~1 s [14]

Poly-gel Immobilized Luminol NO2 sensor

460 ppt

0.5 - 20 ppb

The gel substrate needs to be replaced every day [15] .

US EPA standard NO2 test method

~1 ppb

1 - 500 ppb

LOD and range will vary slightly on different conditions [10] .

Non- Chemiluminescence

Cavity Attenuated Phase Shift (CAPS) NO2 detector

0.3 ppb

0.5 - 200 ppb

Very fast response, suitable for online monitoring [17] [18]

CAPS NO2 detector, second generation

0.06 ppb

0 - 320 ppb

Improved accuracy and sensitivity [19]

Miniature fiber-optic spectroscopy

~10 ppb

15 - 50 ppb

Semi quantitative with a relatively large error (±20%) [20]

DPPD-polymer NO2 detector

0.12 ppm

0.1 - 25 ppm

Small scale integrated sensor [21]