An odor detection device (1) includes an odor sensor (10), environmental information measurement means (11, 12), odor information collection means (20), difference information acquisition means (21), and correction means (22). The odor sensor (10) detects information on an odor emitted from an odor source (2). The environmental information measurement means (11, 12) measures information on an environment, correlated with the amount of water vapor contained in surrounding gas. The difference information acquisition means (21) acquires the difference amount of water vapor, indicating a difference between information on an environment surrounding the odor sensor (10) and information on an environment surrounding the odor source (2). The correction means (22) corrects information on an odor, collected by the odor information collection means (20), on the basis of difference information acquired by the difference information acquisition means (21).

An exhaust gas analysis device analyzes exhaust gas generated when fuel is combusted. This exhaust gas analysis device includes a first analyzer that measures a concentration of a component to be measured in the exhaust gas, a second analyzer that measures a concentration of CO.sub.2 in the exhaust gas, a storage portion that stores a hydrogen/carbon ratio, which is a ratio between hydrogen and carbon composing the fuel, or an input receiving portion that receives an input of the hydrogen/carbon ratio, a moisture concentration estimating portion that, based on the measured CO.sub.2 concentration and on the hydrogen/carbon ratio of the fuel, estimates a concentration of moisture in the exhaust gas, and a correcting portion that, based on the estimated moisture concentration, corrects the measured concentration of the component to be measured.