Abstract

Real-time imaging of gas leaks was demonstrated using an IR camera employing outdoor thermal background radiation. Ammonia, ethylene and methane detection was demonstrated in the spectral region 7–13 µm. Imaging was accomplished using an optical filter and a gascorrelation cell matching the absorption band of the gas. When two gases, such as ammonia and ethylene, are absorbing in the same wavelength region it is possible to isolate one for display by using gas-correlation multispectral imaging. Results from a field test on a leaking gas tanker are presented as QuickTime movies. A detection limit of 200 ppm×meter for ammonia was accomplished in this setup when the temperature difference between the background and the gas was 18 K and the frame rate was 15 Hz.

© Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |

  1. T.J. Kulp, P.E. Powers and R. Kennedy, "Remote imaging of controlled gas releases using active and passive infrared imaging systems," in Infrared Technology and Applications XXIII, B.F. Andresen, M. Strojnik Scholl, eds., Proc. SPIE 3061, 269-278 (1997).
  2. S.-�. Ljungberg, T.J. Kulp and T.G. McRae, "State-of the-art and future plans for IR imaging of gaseous fugitive emission," in Thermosense XIX, R.N. Wurzbach, D.D. Burleigh, eds., Proc. SPIE 3056, 2-19 (1997).
  3. C. Allander, P. Carlsson, B. Hall�n, B. Ljungqvist and O. Norlander, "Thermocamera a macroscopic method for the study of pollution with nitrous oxide in operating theatres," Acta Anaesth. Scand. 25, 21-24 (1981).
    [CrossRef] [PubMed]
  4. T.G. McRae and T.J. Kulp, "Backscatter absorption gas imaging: a new technique for gas visualization," Appl. Opt. 32, 4037-4050 (1993).
    [PubMed]
  5. J. Sandsten, H. Edner and S. Svanberg, "Gas imaging by infrared gas-correlation spectrometry," Opt. Lett. 21, 1945-1947 (1996), http://www-atom.fysik.lth.se/JonasSandsten/GasCorrelationImaging.htm.
    [CrossRef] [PubMed]
  6. T.V. Ward and H.H. Zwick, "Gas cell correlation spectrometer: GASPEC," Appl. Opt. 14, 2896-2904 (1975).
    [CrossRef] [PubMed]
  7. H.S. Lee and H.H. Zwick, "Gas filter correlation instrument for the remote sensing of gas leaks," Rev. Sci. Instr. 56, 1812-1819 (1985).
    [CrossRef]
  8. H. Edner, S. Svanberg, L. Un�us and W. Wendt, "Gas-correlation lidar," Opt. Lett. 9, 493-495 (1984).
    [CrossRef] [PubMed]
  9. P.S. Andersson, S. Mont�n and S. Svanberg, "Multi-spectral system for medical fluorescence imaging," IEEE J. Quant. Electr. QE-23, 1798-1805 (1987).
    [CrossRef]
  10. L.S. Rothman, C.P. Rinsland, A. Goldman, S.T. Massie, D.P. Edwards, J.-M. Flaud, A. Perrin, C. Camy-Peyret, V. Dana, J.-Y. Mandin, J. Schroeder, A. McCann, R.R. Gamache, R.B. Wattsin, K. Yoshino, K.V. Chance, K.W. Juck, L.R. Brown, V. Nemtchechin, P. Varanasi, The HITRAN molecular spectroscopic database: 1996 edition., J. Quant. Spectrosc. Radiat. Transfer 60, 665-710 (1998).
    [CrossRef]
  11. M.L. Polak, J.L. Hall and K.C. Herr, "Passive Fourier-transform infrared spectroscopy of chemical plumes: an algoritm for quantitative interpretation and real-time background removal," Appl. Opt. 34, 5406-5412 (1995).
    [CrossRef] [PubMed]
  12. P.L. Hanst, QASoft �96, Database and quantitative analysis program for measurements of gases, Infrared Analysis Inc., Anaheim, Ca, 1996.
  13. GRAMS/32, Array basic programming language, Galactic Industries Corp.

Other

T.J. Kulp, P.E. Powers and R. Kennedy, "Remote imaging of controlled gas releases using active and passive infrared imaging systems," in Infrared Technology and Applications XXIII, B.F. Andresen, M. Strojnik Scholl, eds., Proc. SPIE 3061, 269-278 (1997).

S.-�. Ljungberg, T.J. Kulp and T.G. McRae, "State-of the-art and future plans for IR imaging of gaseous fugitive emission," in Thermosense XIX, R.N. Wurzbach, D.D. Burleigh, eds., Proc. SPIE 3056, 2-19 (1997).

C. Allander, P. Carlsson, B. Hall�n, B. Ljungqvist and O. Norlander, "Thermocamera a macroscopic method for the study of pollution with nitrous oxide in operating theatres," Acta Anaesth. Scand. 25, 21-24 (1981).
[CrossRef] [PubMed]

T.G. McRae and T.J. Kulp, "Backscatter absorption gas imaging: a new technique for gas visualization," Appl. Opt. 32, 4037-4050 (1993).
[PubMed]

J. Sandsten, H. Edner and S. Svanberg, "Gas imaging by infrared gas-correlation spectrometry," Opt. Lett. 21, 1945-1947 (1996), http://www-atom.fysik.lth.se/JonasSandsten/GasCorrelationImaging.htm.
[CrossRef] [PubMed]

T.V. Ward and H.H. Zwick, "Gas cell correlation spectrometer: GASPEC," Appl. Opt. 14, 2896-2904 (1975).
[CrossRef] [PubMed]

H.S. Lee and H.H. Zwick, "Gas filter correlation instrument for the remote sensing of gas leaks," Rev. Sci. Instr. 56, 1812-1819 (1985).
[CrossRef]

H. Edner, S. Svanberg, L. Un�us and W. Wendt, "Gas-correlation lidar," Opt. Lett. 9, 493-495 (1984).
[CrossRef] [PubMed]

P.S. Andersson, S. Mont�n and S. Svanberg, "Multi-spectral system for medical fluorescence imaging," IEEE J. Quant. Electr. QE-23, 1798-1805 (1987).
[CrossRef]

L.S. Rothman, C.P. Rinsland, A. Goldman, S.T. Massie, D.P. Edwards, J.-M. Flaud, A. Perrin, C. Camy-Peyret, V. Dana, J.-Y. Mandin, J. Schroeder, A. McCann, R.R. Gamache, R.B. Wattsin, K. Yoshino, K.V. Chance, K.W. Juck, L.R. Brown, V. Nemtchechin, P. Varanasi, The HITRAN molecular spectroscopic database: 1996 edition., J. Quant. Spectrosc. Radiat. Transfer 60, 665-710 (1998).
[CrossRef]

M.L. Polak, J.L. Hall and K.C. Herr, "Passive Fourier-transform infrared spectroscopy of chemical plumes: an algoritm for quantitative interpretation and real-time background removal," Appl. Opt. 34, 5406-5412 (1995).
[CrossRef] [PubMed]

P.L. Hanst, QASoft �96, Database and quantitative analysis program for measurements of gases, Infrared Analysis Inc., Anaheim, Ca, 1996.

GRAMS/32, Array basic programming language, Galactic Industries Corp.

Supplementary Material (5)

» Media 1: MOV (2087 KB)     
» Media 2: MOV (1689 KB)     
» Media 3: MOV (1850 KB)     
» Media 4: MOV (1657 KB)     
» Media 5: MOV (1904 KB)     

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (12)

Fig. 1.
Fig. 1.

Top: Atmosphere transmittance through 300 meters of urban air [12]. Bottom: Spectral radiance of five blackbody radiators (left axis) and the normalized spectral response curve of our IR camera (right axis).

Fig. 2.
Fig. 2.

The normalized spectral response of the IR camera (dark blue curve) is convoluted with the transmittance of two different gas cell window materials and optical filter profiles, yielding two regions of relative response (black curves). The gases are both shown in absorbance at concentrations of 200 ppm×m.

Fig. 3.
Fig. 3.

A. Ammonia transmittance spectrum at a concentration of 400 ppm×m, convoluted with the system response. The black envelope integrated transmittance (no gas) divided by the integrated transmittance under the gas spectrum corresponds to the transmittance of the system. B. Ammonia transmittance spectrum at a concentration of 4000 ppm×m, convoluted with the system response.

Fig. 4.
Fig. 4.

Resulting calibrated ammonia gas concentration. Integrating the black envelopes in Fig. 3 corresponds to a transmittance value of one. Arrows A and B correspond to the integrated transmittance of the spectra in Fig. 3.

Fig. 5.
Fig. 5.

Theoretically calculated relative transmittance through 20000 ppm×m ammonia gas as a function of ΔT=TB-TG with TG=294 K. The results of an experimental verification are inserted with error bars in the figure.

Fig. 6.
Fig. 6.

Measurement scenario and optical arrangements.

Fig. 7.
Fig. 7.

(2 MB) Movie of an ammonia leak, left: by direct absorption and right: by gas-correlation. Binary gas images merged with visible images. Measurement conditions: Time 14:30, Air temperature 18 °C, Surface temperature 36 °C, Relative humidity 48 %, Gas flow 100 l/min, ZnSe gas cell with ammonia at 1 atm., Filter: Spectrogon LP9200.

Fig. 8.
Fig. 8.

(1.7 MB) Movie of an ethylene leak, left: by direct absorption and right: by gas correlation. Measurement conditions: Time 15:10, Air temperature 20 °C, Surface temperature 38 °C, Relative humidity 50 %, Gas flow 10 l/min, ZnSe gas cell with ethylene at 1 atm., Filter: Spectrogon LP9200

Fig. 9.
Fig. 9.

(1.8 MB) Movie of a methane leak, left: by direct absorption and right: by gas correlation. Measurement conditions: Time 15:40, Air temperature 22 °C, Surface temperature 40 °C, Relative humidity 50 %, Gas flow 90 l/min, CaF2 gas cell with methane 1 atm., Filter: Spectrogon BBP7040-8500

Fig. 10.
Fig. 10.

(1.8 MB) Movie of an ammonia leak, color-scale concentration image. Measurement conditions: Time 14:30, Air temperature 18 °C, Surface temperature 36 °C, Relative humidity 48 %, Gas flow 10-100 l/min, ZnSe gas cell with ammonia at 1 atm., Filter: Spectrogon LP9200.

Fig. 11.
Fig. 11.

(1.9 MB) Simultaneous imaging of ammonia and ethylene leaks showing the isolation of the ammonia flow using the gas-correlation technique. Measurement conditions: Time 17:25, Air temperature 19.2 °C, Surface temperature 31.5 °C, Relative humidity 50 %, Ammonia gas flow 15 l/min, Ethylene gas flow 10 l/min, ZnSe gas cell with ammonia 1 atm., Filter: Spectrogon LP9200.

Fig. 12.
Fig. 12.

Absorbance spectra of ammonia, ethylene and methane (200 ppm×m). Water vapor is interfering with methane. IR camera system relative response (black curves).

Metrics