- New FEM for NO2: Our Model 405 nm NO2/NO/NOx Monitor has been designated as a Federal Equivalent Method for NO2 (EQNA-0217-243). In the Model 405 nm, the NO2 is measured directly by absorbance at 405 nm, analogous to an ozone monitor. This approach distinguishes the Model 405 nm from chemiluminescence-based instruments, in which NO2 must be converted to NO using either a molybdenum or photolytic converter with highly variable efficiency. The wavelength of 405 nm was chosen because no other species found in ambient air has significant absorbance at that wavelength, making the Model 405 nm extremely selective for NO2. The versatile Model 405 nm also measures NO and NOx (NO by conversion to NO2 using ozone, and NOx is determined as the sum of NO2 plus NO). More info
- As of December 2016, SD flash memory data logging is now standard on our Model 202 and Model 205 Ozone Monitors.