Measuring device and elevator device

A measurement device (12) is provided with an imaging device (13), a light source (14), an outer diameter calculation unit (21), a distance calculation unit (22), and a correction unit (23). An imaging device (13) captures an image of a long body along the X-axis and outputs image data. The light source (14) emits light diffused in the YZ plane and irradiates the elongated body with linear light. The distance calculation unit (22) calculates the distance from the imaging device (13) to the long body on the basis of the position of the light from the light source (14) in the image data. A correction unit (23) corrects the outer diameter calculated by the outer diameter calculation unit (21) on the basis of the distance. 测定装置(12)具备摄像装置(13)、光源(14)、外径计算部(21)、距离计算部(22)以及校正部(23)。摄像装置(13)拍摄沿X轴的长条体，并输出图像数据。光源(14)放出在YZ平面扩散的光，对长条体照射直线状的光。距离计算部(22)根据图像数据上的来自光源(14)的光的位置来计算从摄像装置(13)到长条体的距离。校正部(23)根据该距离来校正由外径计算部(21)计算出的外径。