Diagram of a Lummer-Brodhun tively, falls on a diffuse white photometer head. surface W. Some of the light which is scattered bythis surface is reflected from the . The Lummer Brodhun Photometer finds wide application in comparison of illuminating power of different light sources. Our L.B. Photometer design and selection. 2 PRINCIPLES OF PHOTOMETRY. 3 LUMMER – BRODHUN PHOTOMETER. 4 PROBLEMS. PH UNIT- 3 LECT – 1. UNIT III LECT – 1. 2. PHOTOMETRY.
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Abstract No abstract available. They first strike a white slab. Password Forgot your password?
Cited by links are available broodhun subscribers only. A Lummer-Brodhun cube is made up of two right-angled prisms that are placed with their hypotenuse sides together to form a cube. This cube directs the light rays coming from both sides of the disk into the eyepiece so that the user can observe the light from both sources simultaneously.
The photometer consists of an opaque screen which can be removed from a box. Not Accessible Your account may give you access. Remember me on this computer.
April 1, Published: Figures 3 You do not have subscription access to this journal. What the observer sees in the eyepiece is two superimposed circles on top of each other, one smaller than the other.
Please login to set citation alerts. Click here to learn more. In the box above the screen are two mirrors and a pair of prisms, which direct the light from the two light sources outside the box into the eyepiece at the top of the box.
Light rays from the two sources enter on either side of the box. Similar to the Weber Photometer this item was designed to compare the brightness of an unknown light source to the brightness of a standard light source. The observer can then see a circular disc of light from one source, surrounded by an halo from the other. When this is accomplished, the luminosity of the unknown source can be calculated.
For a fuller description, see the following website. On either side of the screen are two large circular apertures in the lummwr of the box.
When the brightness are identical, the two circles become one. The light that is reflected off each side of the disk is directed through a right angled prism and towards a Lummer-Brodhun cube.
OSA | A New Principle and its Application to the Lummer-Brodhun Photometer
Journal of the Optical Society of America Vol. You do not have subscription access to this journal. You may subscribe either as an OSA member, or brodhin an authorized user of your institution. Click here to see what’s new.