Stationary nonlaser gas analyzers have been designed since the 1990s at the Institute of Monitoring of Climatic and Ecological Systems, Siberian Branch, Russian Academy of Sciences, on the basis of the classical differential absorption method for monitoring the content of nitrogen and sulfur oxides in exhaust gases of thermal power plants, which burn natural gas, coal, and fuel oil. The operation of gas analyzers at Russian thermal power plants has shown their high sensitivity, reliability, and ease of maintenance. Based on the differential optical absorption spectroscopy and UV LEDs, a prototype of a portable energy-independent gas analyzer has been designed. It is an effective tool for simultaneous long-path measurements of concentrations of several atmospheric gases. An atomic absorption mercury analyzer has been created, where a capillary lamp with mercury of natural isotopic composition and the transverse Zeeman effect is used as a radiation source. A technique for detecting mercury in different media has been designed; the sensitivity of the analyzer is 14 ng/m(3). Its applicability to multipurpose mercury monitoring is shown.