Equipment Calibration Method for Seawater Refractive Index Based on Distilled Water

Abstract

When measurement equipment for marine refractive index is calibrated, the existing calibration methods have problems such as low quantity, high price, and complicated operation. Based on the existing empirical model of seawater refractive index, the dynamic range of the corresponding refractive index was calculated with reference to the dynamic range of temperature and salinity in the range of 0–2 000 m in the South China Sea. This paper also proposed an equipment calibration method for measuring seawater refractive index based on distilled water. The distilled water medium was selected, and within the dynamic range of refractive index suitable for marine measurement, a refractive index measurement experiment with a temperature interval of 0.1 °C was carried out. By comparing with the theoretical interpolation value of the Tilton empirical model, the accuracy of the theoretical value obtained by the empirical model was verified, and a credible data set was selected for the subsequent calibration and application of the equipment for measuring seawater refractive index based on distilled water.

Keywords

• seawater refractive index
• distilled water
• temperature
• salinity
• equipment calibration