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Cerex - Model OP-FTIR (Standard) -Air Sentry FTIR Multi-Gas Analyzer
Optical, remote sensing, sub parts-per-billion (ppb) to percent level gas analyzer. The Cerex Air Sentry was the first open path FTIR to be commercialized and has continued to lead the industry with reliable performance and innovative features. It performs chemical detection and quantification of compounds using open-path, Fourier Transform InfraRed (FTIR) Differential Optical Absorption Spectroscopy (DOAS).
Cerex Air Sentry FTIR
- 1000+m of optical path length
- 350 gases to monitor simultaneously
- 2 parts that require regular maintenance
It is the recognized choice in open-path FTIR and the most reliable for monitoring industrial facilities, accidental releases, and hazardous waste site emissions.
- Monitors from 1 to 1,000 meters
- Eliminates need for many single point gas-specific sensors
- No lengthy calibrations or time-consuming laboratory analysis
- Deep sensitivity – detects concentration of gases that traditional sensor arrays can’t
Weight 150 lbs (68kg)
Measurements 24.5″ x 18.5″ x 12″ (62cm x 47cm x 30.48cm)
Enclosure 4X – IP54, thermoelectrically cooled
Power 4A/2A @ 110/220 VAC
Operating Temperature -20°F – 104°F (-29°C – 40°C)
Optical Path Length 5m – 1000m
Installation
- Suitable for corrosive environment system deployment
- Tripod mountable for semi-permanent installations
We recommend sheltering against wind and solar loading for permanent installations
Maintenance
- Recommend semi-annual inspections of dirt buildup on the exterior heat-sink fins.
- Rinse air conditioner fins as needed
- Fans are rated to 40,000 hours at 40°C
- IR source life time is approximately 2 years
- Stirling cooler (detector cryocooler) guaranteed for 2 years before refurbishment is required
- A maintenance free, thermoelectrically (TE) cooled, detector is available for some applications
Open Path FTIR Technology
The Cerex AirSentry FTIR operates by sending a beam of Infrared light through the open air. In a mono-static installation, the IR beam is reflected back to the analyzer by a retro-reflector array, where the absorption due to target gases is measured and recorded. The analyzer uses a classical least squares regression analysis to compare the measured absorption spectrum to calibrated reference absorption spectra files per USEPA TO-16 Methodology. Beer’s Law is used to report accurate gas concentrations.
Fourier transform infrared spectroscopy (FTIR) is the preferred technique used to obtain an infrared spectrum of absorption or emission of a solid, liquid, and gas.
The Cerex AirSentry FTIR is the only commercial open-path FTIR evaluated in 2 US EPA site studies and proven capable of detecting, identifying, and quantifying air toxins.
(Above) Process of open-path monitoring (depicted with a Cerex UV Sentry). Similarly, the AirSentry FTIR mounts to a precision pan and tilt head which may be used with a tripod for rapid deployment, or with a fixed mount for permanent installations. The retro-reflector array is housed in a NEMA enclosure and may be tripod or fixed mounted to a mast, pole or superstructure. Monitoring path lengths are typically configured to meet minimum detection limits required for the project. Paths to 1 km are possible. The IR beam is eye-safe and the analyzer may be located directly in the breathing zone. Gases present in the beam path are identified and quantified in near real time. Credit: STI
The most cost effective perimeter & fenceline monitoring solution
Offering real time quantification of multiple compounds, the Cerex AirSentry FTIR provides a cost effective multi-component perimeter fugitive emissions or LDAR monitoring solution.
Low maintenance and low detection limits
Monitoring as few as two gases with the AirSentry FTIR often results in lower initial and lower ongoing operational costs than utilization of competing gas detection technologies, while simultaneously delivering reliable U.S.E.P.A. TO-16 regulatory compliant air quality monitoring.
Individual species of prolific hazardous air pollutants
The AirSentry FTIR is offered fully configured to meet the requirements of your air quality monitoring application. Target gases are selected from Cerex’s library of 385 compounds.
Extensive Library with Options for Customization
Cerex has over 385 compounds available for detection with the AirSentry. If your compound is not one of the compounds already available within our database, the Cerex AirSentry FTIR may import gas spectra from the numerous FTIR databases on the web (NIST, EPA, PNNL, etc.)
If you have a compound that is not available in a public database, we may be able to work with you to develop a custom spectrum. Detection limits are a function of the IR detector, installed path length, and site conditions. The detection limits shown have been empirically determined from bump tests of fielded instruments at full path-length.
It is efficient as an alarm and easily integrated into your existing alarm system.
*NOTE: If desired target gases are available within the UV spectrum, we recommend the Cerex UV SENTRY for better pricing options. The UV Sentry is an open-path analyzer that uses UV-DOAS (Ultra Violet Differential Optical Absorption Spectroscopy). Find more information about UV-DOAS and FTIR techniques here.
- Air Sentry FTIR Common Target Gases
- Acetaldehyde (C2H4O)
- Acetic Acid (C2H4O2)
- Acetone (CH3COCH3)
- Acetylene (C2H2)
- Acrolein (C3H4O)
- Benzaldehyde (C7H6O)
- Butane (C4H10)
- n-Butyl (C6H12O2)
- Carbon Dioxide (CO2)
- Carbon Monoxide (CO)
- Chlorine Dioxide (ClO2)
- Ethane (C2H6)
- Ethanol (C2H6O)
- Formaldehyde (CH2O)
- Formic Acid (CH2O2)
- n-Hexane (C6H14)
- Hydrogen Bromide (HBr)
- Hydrogen Chloride (HCl)
- Hydrogen Fluoride (HF)
- Methane (CH4)
- Nitric Oxide (NO)
- Nitrogen Dioxide (N2O)
- Phenol (C6H5OH)
- Phosgene (CCl2O)
- Water Vapor (H2O)
Cerex recognizes that detailed gas monitoring results need to be reliable and available quickly to various stakeholders. For this reason, Cerex engineers developed software to accurately detect and display gases within the air in real time from any location.
On an Air Sentry FTIR, a user can see results remotely on a phone, tablet, or computer anywhere in the world via a virtual connection. GPS and cellular configurations make this possible in isolated environments.
All data is automatically saved in an easy to access .csv file; this feature helps our clients in various ways - from daily use to crucial events such as evidence in court. Early detection translates into quicker response times, reduced environmental impact, decreased plant downtime, and reduced exposure to site personnel and the community.
Hundreds of successful installations
In 2019 alone, 190 Air Sentry units were provided to various clients
Cerex has been manufacturing the AirSentry FTIR since 1994 and continues to provide support for these fielded instruments. 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.
The AirSentry FTIR, with its hundreds of detectable compounds, is suitable choice for compliance with Rule 1180 and refinery fenceline air monitoring. 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.