. English: Diagram of microwave spectrometer apparatus built by Indian scientist Jagadish Chandra Bose in his pioneering experiments with microwaves between 1894 and 1897. The drawing is from his 1897 paper. It consists of a spark-gap transmitter (left) which generated 12 - 60 GHz microwaves, a receiver using a junction detector consisting of fine steel springs mounted in a horn antenna, connected to a bias battery and galvanometer. The transmitter waveguide and receiving horn were pointed at an optical stand on which reflectors, diffraction gratings and prisms could be mounted, which Bose use
. English: Diagram of microwave spectrometer apparatus built by Indian scientist Jagadish Chandra Bose in his pioneering experiments with microwaves between 1894 and 1897. The drawing is from his 1897 paper. It consists of a spark-gap transmitter (left) which generated 12 - 60 GHz microwaves, a receiver using a junction detector consisting of fine steel springs mounted in a horn antenna, connected to a bias battery and galvanometer. The transmitter waveguide and receiving horn were pointed at an optical stand on which reflectors, diffraction gratings and prisms could be mounted, which Bose used to measure reflection, refraction, index of refraction, diffraction, and polarization of the waves. The radial arm holding the receiving horn could be rotated to any angle about the stand, to measure the angle of the refracted beam. In these experiments, Bose was first to generate microwaves, and invented the microwave horn antenna, waveguide, and crystal radio wave detector. The labeled parts are described in the source as: (R) Spark-gap transmitter, with a Righi spark gap consisting of 3 tiny platinum beads, driven by an induction coil, contained inside an iron box to prevent the magnetic field of the coil from interfering with the receiver. The microwaves passed out through a cylindrical or rectangular waveguide, pointed at the stand (T) Key. When it was pressed, a single spark would jump across the spark gap, creating a short pulse of microwaves (S) Spectrometer circle stand, graduated in degrees (M) Plane mirror (F) Receiver horn with detector consisting of fine steel springs compressed in box (t) Thumbscrew to adjust pressure on detector (G) Galvanometer attached to detector (V) Liquid battery to bias detector (r) Potentiometer to adjust bias (C) Concave mirror (p) Prism (P) Half-cylinders for demonstrating internal reflection (K) Crystal holder for testing transmission of minerals . 27 March 2012. Jagadish Chandra Bose 305 Jagadish Chandra Bose microwave apparatus
Size: 2856px × 1750px
Photo credit: © The Picture Art Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords:
