Abstract: Certain embodiments of the present invention provide a refractometer including: a housing having an immersion portion, the immersion portion having an opening; a light source for emitting a light; a light sensor for converting a received light into an electrical signal; a prism including faces, including: a first face proximal to the light source and the light sensor; a second face, at least a portion of the second face configured for contacting a sample liquid through the opening, and for forming an interface between the second face and the sample liquid; and a third face, wherein the light travels by: being directed towards the second face; being reflected at least in part by the interface towards the third face; and being reflected at least in part by the third face towards the light sensor. In an embodiment, the refractometer further includes a control portion for receiving the electrical signal, and for determining a refractive index of the sample liquid based at least in part on the electrical signal.

Abstract: Certain embodiments of the present invention provide a refractometer including: a housing having an immersion portion, the immersion portion having an opening; a light source for emitting a light; a light sensor for converting a received light into an electrical signal; a prism including faces, including: a first face proximal to the light source and the light sensor; a second face, at least a portion of the second face configured for contacting a sample liquid through the opening, and for forming an interface between the second face and the sample liquid; and a third face, wherein the light travels by: being directed towards the second face; being reflected at least in part by the interface towards the third face; and being reflected at least in part by the third face towards the light sensor. In an embodiment, the refractometer further includes a control portion for receiving the electrical signal, and for determining a refractive index of the sample liquid based at least in part on the electrical signal.

Abstract: A refractometer for measuring refractive index of a sample comprising a prism having an interface contacting the sample, a light source that radiates light towards the interface from an entrance face of the prism, and a photoelectric sensor for receiving light reflected at the interface and directed outward from an exit face of the prism. The light source and the photoelectric sensor are secured to the prism. The refractometer comprises a sample stage arranged surrounding the interface surface. This sample stage provides a non-adhesive coating formed on the surface thereof. The refractometer comprises filter means arranged between the interface surface and the photoelectric sensor. This filter means includes a wavelength filter that selectively allows transmission of light having a wavelength within a prescribed region, including a wavelength of light of the light source.

Abstract: A refractometer for measuring refractive index of a sample comprising a prism having an interface contacting the sample, a light source that radiates light towards the interface from an entrance face of the prism, and a photoelectric sensor for receiving light reflected at the interface and directed outward from an exit face of the prism. The light source and the photoelectric sensor are secured to the prism. The refractometer comprises a sample stage arranged surrounding the interface surface. This sample stage provides a non-adhesive coating formed on the surface thereof. The refractometer comprises filter means arranged between the interface surface and the photoelectric sensor. This filter means includes a wavelength filter that selectively allows transmission of light having a wavelength within a prescribed region, including a wavelength of light of the light source.