The GUV-15H PM10 High Volume Air Sampler, manufactured by Thermo Electron Corporation, is a FRM filter-based sampler that yields continuous measurements of coarse particle concentrations, composition, size, and other properties. The
GUV-15H contains a PM10 volumetric flow controller that regulates flow at a constant but unadjustable rate.

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) analyzer, manufactured by Thermo Electron Corporation, 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.

The ozone analyzer, manufactured by Thermo Electron Corporation, 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.

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 scatting coefficient of particles 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 expressed in visual range (km), or deciview (dv).

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.