Refractometer
A refractometer device used for the measuring the refractive index of samples using the concepts of critical angle and total internal reflection. Holmarc's Refractometer (Model No: HO-ED-O-03) is an experimental model designed for understanding the basics of refractometry.
In this experiment, the sample is placed on a dove prism made of high refractive index. LED light of wavelength 589nm is collimated and directed to the interface between the prism and the solution. The light rays meet the interface at different angles. Some of these angles are larger than the critical angle of the interface so that light is totally reflected. For angles of incidence smaller than the critical angle, light is partially transmitted (i.e. lost). Thus a shadow (less luminescence) is created on the screen. From the position of the shadow line we can find the refractive index.
Bright LED light is used here. Fine adjustments in grazing or incident angle can be done using kinematic tuning of the LED mount. The lenses and dove prism are fixed on rail carriers which are held on graduated solid aluminum rail. All the mounts are made of anodized aluminum and can be mounted easily on the optical rail.
Experiment:
To find the refractive index of an unknown solution.
Features:
Refractive index measurement is easy
Compact and precision design
High performance LED light source of optical wavelength 589nm
Precise optics minimize aberrations
Can observe clear and sharp shadow line
Mounts and rail with black anodized finish
Drawings:
