A sensor device includes a first light emitter that emits light with a wavelength from a first spectral range, a second light emitter that emits light with a wavelength from a second spectral range, a first light detector configured to detect light with a wavelength from the first spectral range, but not to respond to light with a wavelength from the second spectral range, and a second light detector configured to detect light with a wavelength from the first spectral range and light with a wavelength from the second spectral range, wherein a distance between the first light emitter and the first light detector is smaller than a distance between the second light emitter and the second light detector.