Cerex Micro FTIR

Real-time laboratory quality measurements within a portable package

A true multi-gas analyzer, the Micro FTIR standard gas detection libraries are built for common applications, including: air toxics monitoring, hospital and anesthetic gas monitoring , and refinery monitoring. The Micro FTIR is also capable of simultaneous monitoring of more than 350 compounds in Cerex’s FTIR library.

Offering true part-per-billion (ppb) detection limits in a simple to operate portable package, the cryo-cooled system can reliably deliver unattended, continuous real time monitoring of ultra low ppb concentrations of individual gas species with absorption features spanning the IR spectrum from 2 to 14 microns.

Cerex Micro FTIR

hours of battery life
0+ gases
to monitor simultaneously
0 parts
that require regular maintenance

Micro FTIR

Weight 38 lbs (17.2kg) or 35 lbs without battery
Measurements 18″ x 14″ x 6.7″ (45.7cm x 35.6cm x 17cm)
Enclosure 4X – IP54
Operating Temperature Short term 0 to 40⁰C, long term 5⁰C to 30⁰C, non-condensing

Minimum Detection Limits Parts per million (ppm)
Optical Path Length: 4 meters


  • Recommend quarterly inspection and possible replacement of the air intake filters if operated continuously
  • Fans are rated to 70,000 hours at 40°C
  • IR source life time is approximately 2 years

How it Works

Portable Point FTIR Technology

The Cerex Micro FTIR operates using a process known as point monitoring. Surrounding ambient gases are channeled into the analyzer via a sample hose or attachment. Following this, an internal cell holds the gas sample for analysis.

Next, with FTIR technology, an infrared light passes through the gas sample contained within the cell. Thanks to an ultra sensitive spectrometer, a physics principle known as the Beer-Lambert Law, and Cerex’s proprietary software (CMS), the gas sample is translated into useable data.

The result of coupling our proven detection system with a 4 meter internal optical sample path and CMS real time analytic software is an industry leading FTIR multi-gas analyzer.

Sensitive, portable solution for ambient air monitoring

Offering real time identification and quantification of criteria pollutants, the Micro FTIR analyzer provides a sensitive yet cost-effective solution in easy to operate, all-in-one packages.

Low maintenance and low detection limits

Parts-per-million (ppm) minimum detection limits, an MCT detector cooled to 77K, high spectral resolution, and a long optical path length maximize the sensitivity of the Micro FTIR

Individual species of prolific hazardous air pollutants

The Micro 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.

Common Detectable Gases

Extensive Library with Options for Customization

Cerex has over 385 compounds available for detection with the Micro FTIR. If your compound is not one of the compounds already available within our database, the Shepherd 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.

Micro 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)

FTIR is not recommended for Benzene and Hydrogen Sulfide monitoring due to poor detection limits; instead, we recommend our UV Sentry (Open Path Detection) or Hound Series (Portable Point Detection) analyzers.


Results You Can Rely On

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 a Micro FTIR, a user can see results on the integrated touchscreen located on the front of the analyzer. Additionally, remotely on a phone, tablet, or computer anywhere in the world via a virtual connection. GPS and cellular configurations make this possible in remote 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.


Real time spectral subtraction and synthetic background implementation allow the Air Sentry to clearly display accurate concentrations of target gases over 1000 meters without interference from other gas species


The Micro FTIR is a viable solution when individual species of infrared (IR) absorbing gases in a non-hazardous atmosphere need to be measured, and high sensitivity point analysis in a portable or transportable package is required.

With detection limits down to parts-per-million (ppm) levels, the Micro FTIR will be the most portable, lightweight choice for ambient monitoring. It may be used for portable stack analysis if installed downstream of a sample conditioning system providing a cool, dry sample. A dilution system may also be required if measuring high PPM levels of combustion gases.

All Applications

Ambient Air Monitoring

Anesthetic / Hospital Monitoring

Chemical Manufacturing AQ

Chemical Warfare Agent Detection

Container Inspection

General Industrial Air Monitoring


Indoor Air Monitoring

Leak Detection

Manufacturing Air Quality

Odor Complaint Response

Refinery Air Quality Fertilizer

Response Border Patrol Inspection

Stationary Source Monitoring (Cool, dry sample)

Micro FTIR Specifications

General Parameters
Model Micro FTIR
Analyzer Type Multi-gas portable point analyzer
Measuring Technology Fourier Transform InfraRed (FTIR) Differential Optical Absorption Spectroscopy (DOAS)
Performance Available with standard HAP (385 compound & 62 Compound), Criteria, Hospital and custom gas detection libraries.
Data Output Rate T90, Typically < 60s, depending on the gas flow and measurement time
Measurement Principle Beer-Lambert Law
Measurement Technique Classical Least Squares (CLS) regression analysis; optional Partial Least Squares (PLS)
Operating Temperature Short term 0°C to 40°C, long term 5°C to 35°C
Storage Temperature -20C° to 60C°; non-condensing
Power Supply 100 to 240VAC / 50-60Hz; 40V Battery 2Ahr, 4Ahr, 6Ahr
Power Consumption Average 120W
Instrument Cooling Air Cooled
Dimensions 18″ x 14″ x 6.7″ (45.7cm x 35.6cm x 17cm)
Weight 38lbs (17.2kg) (35lbs without battery)
Measuring Parameters
Concentration measurement accuracy ± 5% of reading TYP
Concentration measurement precision ± 5% of reading TYP
Interferent Mitigation Proprietary adaptive analysis and false positive rejection routines
Zero point calibration Automatic and manual zero point
Real Time Operating Software Cerex Continuous Monitoring Software (CMS)
Operating System Windows 10 Pro
Post Collection Analysis Software Cerex Data Processor
Apodized Resolution User configurable: 1cm-1, 2cm-1, 4cm-1, 8cm-1, 16cm-1, 32 cm-1
Best resolution 0.6cm-1
Scan frequency 6 scans/s @ 32 cm-1
Detector Standard DTGS or
Peltier Cooled MCT (optional)
Detector temperature 77 K (Stirling cooled MCT)
Source SiC, 1550K
Beamsplitter ZnSe (standard)
Window material ZnSe (standard)
Wavenumber range 600-4200 cm-1
Temperature stability < 1% per C⁰
Frequency repeatability < 0.001 cm-1 @ 1918cm-1
Frequency accuracy < 0.06 cm-1 @ 1918cm-1
Short term stability < 0.09%
Maximum signal to noise ratio 50,000: 1 (RMS, 60s, 4 cm-1, at peak response)
Signal sampling 24-bit ADC
Quality Assurance Hardware
Type Internal linear multi-pass cell permanently mounted in beam path. External window removable.
Calibration gas inlet ½” Quick Coupling: ¼” Swagelok test adaptor provided
Calibration gas outlet Case Vent: ⅜" OD push-to-connect tube adaptor provided
Path Length 4.88 m
Volume 3.4 L
Maximum sample pressure 1 PSI
Pressure and temperature measurement Integrated pressure and temperature sensor
HMI Touchscreen (standard model)
Digital Interface RJ45 Ethernet LAN Port for local or internet based remote data and access using MODBUS TCP, VNC, and remote desktop.  Spectral data may be stored locally, on a NAS, or disabled. Industrial external wireless option available. Type A USB for data retrieval and peripheral accessories.
Power Connection Environmentally sealed circular Amphenol bayonet connector.
Integrated Computer Embedded industrial PC
Integrated Wind Mapping Three dimesnional ultrasonic anemometer with temperature measurement. Data integrated into CMS data tables and available via MODBUS.
Integrated Data Acqusition External ports with data integration for particulate or ancillary co-located analyzers (TDLAS laser, electrochemical, etc.).
Data Output MODBUS over RS-232, RS-485.  MODBUS over TCP-IP is standard.
Analog Output 8 channel configurable 0-24mA (4-20mA with extended range)

Discuss your project with our application specialists

Our engineers have decades of experience in creating custom solutions to meet your monitoring challenges