Gas Leak Detection by Dilution of Atmospheric Oxygen
AbstractGas leak detection is an important issue in infrastructure monitoring and industrial production. In this context, infrared (IR) absorption spectroscopy is a major measurement method. It can be applied in an extractive or remote detection scheme. Tunable laser spectroscopy (TLS) instruments are able to detect CH4 leaks with column densities below 10 ppm·m from a distance of 30 m in less than a second. However, leak detection of non-IR absorbing gases such as N2 is not possible in this manner. Due to the fact that any leaking gas displaces or dilutes the surrounding background gas, an indirect detection is still possible. It is shown by sensitive TLS measurements of the ambient background concentration of O2 that N2 leaks can be localized with extractive and standoff methods for distances below 1 m. Minimum leak rates of 0.1 mbar·L/s were determined. Flow simulations confirm that the leakage gas typically effuses in a narrow jet. The sensitivity is mainly determined by ambient flow conditions. Compared to TLS detection of CH4 at 1651 nm, the indirect method using O2 at 761 nm is experimentally found to be less sensitive by a factor of 100. However, the well-established TLS of O2 may become a universal tool for rapid leakage screening of vessels that contain unknown or inexpensive gases, such as N2. View Full-Text
Share & Cite This Article
Lambrecht, A.; Maier, E.; Pernau, H.-F.; Strahl, T.; Herbst, J. Gas Leak Detection by Dilution of Atmospheric Oxygen. Sensors 2017, 17, 2804.
Lambrecht A, Maier E, Pernau H-F, Strahl T, Herbst J. Gas Leak Detection by Dilution of Atmospheric Oxygen. Sensors. 2017; 17(12):2804.Chicago/Turabian Style
Lambrecht, Armin; Maier, Eric; Pernau, Hans-Fridtjof; Strahl, Thomas; Herbst, Johannes. 2017. "Gas Leak Detection by Dilution of Atmospheric Oxygen." Sensors 17, no. 12: 2804.
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.