Abstract
A portable sensor has been developed that is capable of producing real-time video images of fugitive methane emissions. Active imaging is performed using a pulsed optical parametric generator, OPG, that illuminates the scene at wavelengths corresponding to an absorption feature of methane near 3.27 um. The imager is capable of displaying single-wavelength images as well as differential-wavelength images. The transmitted radiation has a fan-shaped beam profile, and the radiation backscattered from surfaces is imaged onto a single row of detectors on a focal plane array. By sweeping the field-of-view, a two-dimensional image is formed in which a methane plume appears as an area of attenuation. Two pulses offset in wavelength can be transmitted to produce a differential image that suppresses background features and enhances gas plume visibility. The ima-ger can be operated with a battery power source and carried by a single operator. Tests were conducted at leak-detection training facilities in Japan, and results are presented here.
