提出一种具有线性响应的圆盘型液体光电折射率计。光线在圆盘内的多次反射显著地消除了非全内反射的影响，有效地改善了测量线性度。这种圆盘型光电折射率计甚至可对非平行入射光束仍保持相当好的线性度。

A Circular disc refractometer with linear output response of photo-electrical signal to liquid refractive index has been developed. The multiple reflection within the circular disc provides a design feature to reduce the influence of non-total internal reflection and significantly improves the measurement linearity. In addition, the circular disc refractometer can achieve quite good linearity even for non-parallel light beams.