The screw gauge is an instrument used for measuring exactly the diameter of a thin wire or the width of a sheet of metal. It comprises of a U-shaped mount which is fixed with a screwed pin which is fixed to a thimble.
Screw Cauge Video Links given below :
A vernier caliper is usually used to measure the diameter of circular objects. The circular jaws of the vernier caliper fit perfectly on the circumference of round objects. Vernier caliper consists of two scales, the main scale which is fixed, and a moving vernier scale. The main scale has readings in millimeters.
Vernier Calliper Video Links given below :
A spectrometer is a device for measuring wavelengths of light over a wide range of the electromagnetic spectrum. It is widely used for spectroscopic analysis of sample materials. The incident light from the light source can be transmitted, absorbed or reflected through the sample.By using Spectrometer we can find angle of prism.