Tunable Diode Laser Nitrogen Dioxide Monitor
The nitrogen dioxide (NO2) violet laser diode based sensor for ambient, airborne and vehicle mounted measurements from ETG Risorse e Tecnologia Srl.
Features
NO2 direct cavity-enhanced absorption measurement at 404 nm
Detection limit of 1 ppbv for a time constant of 1 s (0.2 ppbv for a time constant of 80 s)
Absolute measurements
Self-calibration
No OZONE generator required
No NO2 to NO converter required
No exhaust scrubber required
No mechanical modulators required
Rugged and reliable
Low operating cost
Typical raw cavity output intensity and phase shift signals observed when sampling laboratory air at a flow rate of 500 sccm, a laser modulation frequency of 60 kHz, a lock-in amplifier time constant of 1 s. An average NO2 concentration in the laboratory air was 24 ± 1 ppbv.(48 ± 2 mg m–3). Signal spikes were due to flow change between laboratory air and chemically scrubbed air.
Applications
Air quality monitoring
Ambient nitrogen dioxide monitoring across cities
Research of NO2 reactions with other species
Ordering Options
RS232, RS485, 4-20mA
Alarm relays
19" rack mountable version
GPRS modem or Ethernet

