Sensitive In Situ Trace Gas Detection by Photothermal Deflection Spectroscopy.

摘要

We present a sensitive (5 ppb ethylene), 10(sup -7) cm(sup -1) and simple photothermal scheme for the detection of trace gases and measuring weak absorptions in gas phase samples. We also demonstrate the feasibility of this scheme for performing in situ measurements in the absence of sample cells or containers, thus eliminating the drawbacks of sampling and sampling techniques. Factors limiting our detectivity are discussed, and a comparison to the thermal lens effect is made.