Liquid refractive index CCD real-time measuring device and measuring method

The invention relates to a liquid refractive index CCD real-time measuring device, wherein the lower end of the inside of a dark cassette is provided with a luminescent element, a diaphragm with a light-admitting orifice is arranged above the luminescent element on the dark cassette, the upper surface of the diaphragm is provided with flat-plate transmitting glass, the upper surface of the flat transmitting glass is provided with flat-plate image display glass with an upper optical surface and a lower frosted surface, a shading cover is arranged on the left side of the dark cassette, and the upper end of the inside of the dark cassette is provided with a CCD camera which is connected with a computer through a cable. A method which adopts the measuring device to measure the liquid refractive index is as follows: liquid to be measured forms a liquid film between the flat-plate transmitting glass and the flat-plate image display glass, visible light penetrates through the light-admitting orifice, the flat-plate transmitting glass and the liquid film of the liquid to be measured to form a circular dark spot using an incident light spot as the centre of the circle on the frosted surface of the flat-plate image display glass; the CCD camera converts the received circular dark spot to a digital signal to output to the computer through a cable, and the computer calculates the refractive index of the liquid to be measured.