The Model O2L measures oxygen in air mixtures for industrial applications with a resolution of 100 ppm from 0 to 10% or with a resolution of 0.1% from 0 to 100%. In addition to the features of the Model O2, the O2L offers a 4-20 mA analog output and four front-panel-programmable alarm contacts. This unit is used, for example, in fuel mixture and combustion emissions analysis.