An optical interferometric range sensor (10; 100), comprising: a light source (51; 110) configured to emit light with a changing wavelength; a light splitter (54a to 54c; 120; 121) configured to split the light emitted from the light source (51; 110) into a plurality of beams to be incident on a plurality of spots; an interferometer configured to generate, for each of the plurality of beams of the split light incident on a corresponding spot of the plurality of spots, interference light based on measurement light and reference light, the measurement light being light emitted from a sensor head (20; 131a, 131b) to a measurement target and reflected from the measurement target, the reference light being light traveling on an optical path at least partially different from an optical path of the measurement light; a light receiver (56a to 56c, 58a to 58c, 71a to 71c, 74a to 74c; 140a to 140c) configured to receive the interference light from the interferometer to convert the interference light to an electric signal; a processor (59, 75; 150) configured to calculate a distance from the sensor head (20; 131a, 131b) to the measurement target based on the electric signal resulting from conversion performed by the light receiver (56a to 56c, 58a to 58c, 71a to 71c, 74a to 74c; 140a to 140c); an identifier configured to identify the sensor head (20; 131a, 131b) based on a beat signal generated by the interferometer; and a light adjuster configured to adjust an amount of light to be emitted from the sensor head (20; 131a, 131b) to the measurement target based on the sensor head (20; 131a, 131b) identified by the identifier, wherein the beat signal results from a portion of the light emitted from the light source (51; 110) and received by the interferometer being reflected from a component (137a, 137b) of the interferometer including a reflective surface. a light source (51; 110) configured to emit light with a changing wavelength; a light splitter (54a to 54c; 120; 121) configured to split the light emitted from the light source (51; 110) into a plurality of beams to be incident on a plurality of spots; an interferometer configured to generate, for each of the plurality of beams of the split light incident on a corresponding spot of the plurality of spots, interference light based on measurement light and reference light, the measurement light being light emitted from a sensor head (20; 131a, 131b) to a measurement target and reflected from the measurement target, the reference light being light traveling on an optical path at least partially different from an optical path of the measurement light; a light receiver (56a to 56c, 58a to 58c, 71a to 71c, 74a to 74c; 140a to 140c) configured to receive the interference light from the interferometer to convert the interference light to an electric signal; a processor (59, 75; 150) configured to calculate a distance from the sensor head (20; 131a, 131b) to the measurement target based on the electric signal resulting from conversion performed by the light receiver (56a to 56c, 58a to 58c, 71a to 71c, 74a to 74c; 140a to 140c); an identifier configured to identify the sensor head (20; 131a, 131b) based on a beat signal generated by the interferometer; and a light adjuster configured to adjust an amount of light to be emitted from the sensor head (20; 131a, 131b) to the measurement target based on the sensor head (20; 131a, 131b) identified by the identifier, wherein the beat signal results from a portion of the light emitted from the light source (51; 110) and received by the interferometer being reflected from a component (137a, 137b) of the interferometer including a reflective surface.