Open Path Air Monitoring

Proven Solutions for Fence-line and Perimeter Ambient Air Monitoring

Offering 40 CFR 63.658, BAAQMD Rule 12-15 and SCAQMD Rule 1180 Compliance


AirSentry FTIR Open Path FTIR

Cerex commercialized the first open path FTIR more than twenty years ago, and has continued to lead the industry with reliable performance and innovative features. With hundreds of detectable compounds, the AirSentry FTIR is the monitoring solution for petrochemical industries, semiconductor plants, agriculture, landfill, and site surveys of historically polluted areas.

A flexible analyzer platform, the AirSentry may be rapidly converted from open path mode to point analyzer mode with the inclusion of an optional sample cell. In open path mode the AirSentry FTIR offers full USEPA TO-16 compliant monitoring. In point analyzer mode the AirSentry FTIR meets a variety of method compliance standards including:

  • USEPA Method 318: Extractive FTIR Method for Measurement of Emissions from Mineral Wool and Wool Fiberglass Industries
  • USEPA Performance Specification 15 for Extractive FTIR CEMS in Stationary Sources
  • USEPA Method 320: Vapor Phase Organic and Inorganic Emissions by FTIR
  • USEPA Method 321: Determination of HCl for Portland Cement Industries
  • NIOSH Method 3800 : Organic and Inorganic Gases by Extractive FTIR Spectrometry
  • ASTM Method D6348-03: Determination of Gaseous Compounds by Extractive Direct Interface Fourier Transform Infrared Spectroscopy

More about the AirSentry FTIR…


Sentry Series Open Path UVDOAS

The Cerex UV Sentry offers high performance, time resolved monitoring of a variety of regulated gases. With part per trillion minimum detection limits for benzene the UV Sentry allows regulatory compliance for SCAQMD Rule 1180 and BAAQMD Rule 12-15 BTEX monitoring. It also represents a stand-alone solution for alternative MACT compliance for USEPA Method 325 refinery fenceline benzene monitoring.

A true multi-gas analyzer solution, fielded units measure acrolein, ammonia, BTEX, butadiene, chlorine, formaldehyde, naphthalene, nitric oxide, nitrogen dioxide, phenol, styrene, sulfur dioxide and more. Path lengths tested to 1300 meters offer gap-less monitoring coverage with hands-off reliability.

More about the UV Sentry…


AirSentry FTIR
PDF (1.4MB)


USEPA, BAAQMD and SCAQMD Refinery Compliance Solutions
PDF (1.4MB)


UV Sentry
PDF (1.4MB)

[button color=”darkgreen” size=”large” caption=”for more information” link=”” align=”center”]Email Cerex[/button]
For emergency response teams requiring the same performance of an open-path monitor without the setup time, our UV Hound, UV Mini-Hound, UV Micro-Hound, and Shepherd FTIR offer part per billion (ppb) detection levels in an easy to use, ultra portable package.