josef
Uploaded by
9 SLIDES
187 VUES
90LIKES

Luminescence Analysis of Decorative Glass Lamp Reflections: Experimental Methods & Results

DESCRIPTION

This study delves into the luminescence of images in a glass oil lamp through reflections, determining sensitivity ranges of the human eye based on reflectance values. Experimental procedures, results, and future implications are examined.

1 / 9

Télécharger la présentation

Luminescence Analysis of Decorative Glass Lamp Reflections: Experimental Methods & Results

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Purpose • To analyze, through theoretical and experimental methods, the relative luminescence of a series of images produced by multiple reflections in a decorative glass lamp • The number of visible images can be used to measure the sensitivity range of the eye

  2. Background • Glass oil lamp from Curry Club Restaurant, East Setauket • Inner walls of the glass have a partially reflective coating • Dimensions: 6.5in x 3in x 3in • Glass walls are 0.25in thick and have a brown tint 0.25 in 11 images 6.5 in 3 in

  3. Background (cont.) Top View • When the flame is viewed at eye level, a series of flame images can be seen • Each consecutive image is dimmer than the last and 11-12 images can be seen in a dark room • The nth image is produced by n-1 reflections • The reflectance of the inner wall determines the relative brightness of the image 1st image 2nd image 3rd image 4th image

  4. Procedure - Part 1 I2 I1 I4 • An He-Ne laser and a photo detector were used to measure I1, I2, I3, and I4to calculate the reflectance of the inner and outer surface and the absorption (t) • Incoming light split between absorption, reflection, and transmission Outer Surface I8 I5 Ro = I2 / I1 t = I6 / I5 I7 I6 Inner Surface Ri = I7 / I6 I3

  5. Measured Intensity Values * Ratio of second run to first run. The second run values are lower because the laser power decreased after warm-up but are consistent with the first run.

  6. Analysis and Results • The values of Ri, Ro, and t were derived from a set of equations that contained the measured values of I1, I2, I3, and I4. • t = 1-a and a = absorption ratio • I5 = I1 - I2 • I6 = t*I5 = t*(I1 - I2) • I7 = I6 - I3 = t*(I1- I2)-I3 • I8 = t*I7 = I4 + I8*(I2/I1) • t2*(I1 - I2)-t*I3 - I4/(1 - (I2/I1)) = 0 • Ro = I2/I1 • Ri = I7/I6 = 1 - I3/(t*(I1 - I2)) Results: Ro = 3.2% t = 40.8% Ri = 42.5%

  7. Procedure - Part 2 Laser Iris Photo Detector 5 spots of decreasing intensity • Laser beam allowed to travel through the lamp  5 visible spots • Photo detector used to measure their intensities in Volts using a 100 kΩ resistor & iris used to isolate the images • The ratio of the spot intensities is Ri2 • Ri2 = 19.099% Lamp

  8. Discussion / Conclusion • The reflectance of the inner surface of the glass lamp (Ri) equals the relative luminescence between the flame images • Ri was measured using two independent methods and the 2 values are in very good agreement • Ri = 43.0 ± 0.5% • This value predicts the relative luminescence of the candle flame as shown in the graph below • The nth image is approximately (0.43)n times as bright as the first image • The 11th image is 10, 760 times brighter than the first • Therefore, the human eye can perceive a range of about 10,000 in intensity at a single instant

  9. Future Study • Testing human visual sensitivity • Determining an optimum reflection-transmittance ratio (applications for sunglasses, tinted glass, etc.) • Analyzing or designing “one-way” mirrors • Analyzing laser cavities

More Related