| 摘要 |
<p>Provided are a V-block refractometer capable of expanding the range of the potential application thereof to areas in which Abbe refractometers are used without adding cost and a refractive index calculation device and refractive index calculation method used in the V-block refractometer. Using measured refractive index values measured using three wavelengths (the helium d line, hydrogen C line, and hydrogen F line wavelengths) of measurement light other than the sodium D line wavelength, a coefficient calculation unit (103) calculates three coefficients included in an approximation formula, and a refractive index calculation unit (104) uses the approximation formula to calculate an approximate refractive index value for the sodium D line wavelength on the basis of the calculated coefficients and the sodium D line wavelength. As a result, it is possible to measure the refractive index of a sample for the sodium D line wavelength without adding a sodium-vapor lamp as a light source.</p> |
