The TEOM series 1400a PM10 monitor collects a direct measurement of particulate mass on a filter that uses tapered element oscillating microbalance (TEOM) technology. Either PM10 or PM2.5 sample options can be used. Mass concentration data are reported in micrograms per cubic meter at standard averaging times of 1, 8, and 24 hours. The 1400a series is EPA certified for continuous PM10 particulate monitoring, and is an EPA-recognized monitor for continuous PM2.5 measurements.

The IMPROVE Version II Modular Aerosol Sampler, developed and refined by the IMPROVE Program (Interagency Monitoring of Protected Visual Environments), is a 4-module filter-based sampler. It collects fine and total aerosol mass on filter substrates. Aerosol analysis techniques of this instrument yield a comprehensive representation of the physical properties of ambient atmospheric aerosols (concentration, chemical composition, size, and other properties).

The NO-NO2-NOx (nitrogen) 42C analyzer is a chemiluminescence-based analyzer. It is based on the principle that nitric oxide (NO) and ozone (O3) react to produce a characteristic luminescence with an intensity linearly proportional to the NO concentration. Nitrogen dioxide must first be transformed into NO before it can be measured using the chemiluminescent technique. An NO measurement is subtracted from an NOx measurement (NO plus converted NO2) to yield an NO2 value. Used in source emissions monitoring as well as ambient air monitoring, the 42C analyzer carries a U.S. EPA Designated Method RFNA-1289-074.

The ozone 49C analyzer is a UV photometric-based analyzer. It is based on the principle that ozone (O3) absorbs UV light. An ambient air sample is drawn into the instrument where detectors measure the intensity of a UV lamp through the ambient sample and ozone concentrations are calculated. Used for ambient air monitoring, the 49C carries a U.S. EPA Designated Method EQOA-0880-047.

The LPV-2 transmissometer, manufactured by Optec, Inc, measures the light extinction coefficient of the atmosphere by measuring the attenuation of light from a light source. The instrument has two primary components: a light source (transmitter), and a light detector (receiver, pictured here). Depending on the expected range of visual air quality, the components are placed from 0.5 to 10 kilometers apart. The receiver-measured transmitter light intensity is compared to the known (calibrated) transmitter light output. The resulting visibility measurements can be expressed in extinction (km-1), visual range (km), or deciview (dv).

The NGN-2 integrating nephelometer, manufactured by Optec, Inc, estimates the atmospheric scattering coefficient of particles (bsp) in the atmosphere by directly measuring the light scattered by aerosols and gases in a sampled air volume. Scattered radiation from an illumination source is integrated over a large range of scattering angles. The nephelometer measures particle scattering without normalizing or standardizing the measurements (by applying the Rayleigh coefficient). The resulting visibility measurements can be used to estimate an upper limit to visual range (km).

Measuring and recording meteorological variables provides the necessary information to understand and measure how air pollutants are transported and dispersed, and to gain a better understanding of local meteorological conditions. Useful meteorological instrumentation or variables include: wind speed and direction, ambient temperature and vertical temperature difference, relative humidity, solar radiation, and atmospheric stability. Meteorological measurements are made with high quality instrumentation with calibrations traceable to National Institute of Standards and Technology (NIST) standards.

The High Resolution Digital Image Acquisition System (HRDC-1), manufactured by Air Resource Specialists, Inc., allows Internet access to real-time images of a monitoring scene. Images provide a visual reference to current and historical appearances of a scene. Scene characteristics include observer visual range, scene contrast, color, texture, clarity, and other descriptive terms.