US Patent 11859969 Measurement device

A measurement device includes: a probe part including a probe configured to measure a surface of an object to be measured and is attached so as to swing around a swing center according to a shape of the surface of the object to be measured; a scale configured to measure displacement by swinging of the probe part; a scale head configured to read a scale mark of the scale; and an arm part to which the probe part is attached, the arm part is attached so as to swing around the swing center integrally with the probe part, and the scale is attached to the arm part. When thermal expansion coefficients of the probe part, the arm part and the scale are α, β and γ respectively, the measurement device satisfies a condition of (α+γ)−1/2α≤β≤(α+γ)+1/2α.