Skip to main content
Article thumbnail
Location of Repository

An open-path, hand-held laser system for the detection of methane gas.

By Ben van Well, Stuart Murray, Jane Hodgkinson, Russ D. Pride, Rainer Strzoda, Graham Gibson and Miles Padgett


We have developed an open-path hand-held gas detector incorporating a distributed feedback InGaAs laser diode at 1.65 µm. Incorporated into a hand-held transceiver unit, the emitted laser beam is backscattered from nearby surfaces, collected and focused onto an amplified InGaAs detector using a 150 mm diameter plastic Fresnel lens. At ranges of 4–5 m, a typical backscattered signal is tens of nanowatts of laser light. Applying second derivative wavelength modulation spectroscopy gives a sensitivity to methane of better than 10 parts per million over a one metre path length. A number of demonstration units have been fabricated and successfully evaluated by end users

Topics: methane, wavelength modulation spectroscopy, instrumentation, infrared spectroscopy, remote detection
Publisher: Institute of Physics
Year: 2005
DOI identifier: 10.1088/1464-4258
OAI identifier:
Provided by: Cranfield CERES

Suggested articles


  1. (1996). A Guide To Gas Safety (Management) Regulations,
  2. (2000). A portable remote methane sensor using a tunable diode laser, doi
  3. (1998). Cavity-locked ring-down spectroscopy, doi
  4. (1981). Direct quantitative-analysis using °ame ionization detection - the construction and performance of the ¯doh detector,
  5. (1992). Frequency modulation and wavelength modulation spectroscopies: comparison of experimental methods using a lead-salt diode laser, doi
  6. (1990). InGaAs/InP distributed feedback quantum well laser, doi
  7. (2000). Quantitative analysis of trace mixtures of toluene and xylenes by CO2 laser photoacoustic spectrometry, doi
  8. (1998). The accuracy and sensitivity of infrared di®erential absorption lidar measurements of hydrocarbon emissions from process units, doi
  9. (1994). Theoretical description of frequency modulation and wavelength modulation spectroscopy, doi
  10. (2003). Wavelength modulation spectroscopy: combined frequency and intensity laser modulation, doi

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.