PROBLEM TO BE SOLVED: To decrease the influence of a disturbance light to a measurement result even when the spectrum of the disturbance light changes according to a surrounding environment.SOLUTION: A measuring device includes: an irradiation means that irradiates an object to be measured with at least either a first measuring light of a first wavelength band or a second measuring light of a second wavelength band a light receiving means that has a first light receiving section that outputs a signal corresponding to the strength of the received light of the first wavelength band and a second light receiving section that outputs a signal corresponding to the strength of the received light of the second wavelength band an irradiation control means that controls the irradiation and stopping of the first measuring light and the second measuring light by the irradiation means a comparing means that acquire the signal output from the first light receiving section and the signal output from the second light receiving section and compares them during the period that the irradiation of the first measuring light and the second measuring light is stopped and a selecting means that selects either the first light receiving section or the second light receiving section as a selected light receiving section according to the comparison result to acquire the signal output from the selected light receiving section during the period that the measuring light enters into the selected light receiving section.COPYRIGHT: (C)2012,JPO&INPIT【課題】周囲環境に応じて外乱光のスペクトルが変化しても、測定結果への外乱光の影響を低減すること。【解決手段】第1波長帯の第1測定光および第2波長帯の第2測定光の少なくとも一方を測定対象物に照射する照射手段と、受光した第1波長帯の光の強度に応じた信号を出力する第1受光部と、受光した第2波長帯の光の強度に応じた信号を出力する第2受光部とを有する受光手段と、照射手段による第1測定光および第2測定光の照射と停止を制御する照射制御手段と、第1測定光および第2測定光の照射が停止されている期間に、第1受光部から出力される信号と第2受光部から出力される信号とを取得して比較する比較手段と、比較結果に応じて、第1受光部または第2受光部のいずれかを選択受光部として選択し、測定光が選択受光部に対して入射されている期間に、選択受光部から出力される信号を取得する選択手段とを具備する。【選択図】図3
