GB438630A - Improvements in photometers - Google Patents
Improvements in photometersInfo
- Publication number
- GB438630A GB438630A GB2832134A GB2832134A GB438630A GB 438630 A GB438630 A GB 438630A GB 2832134 A GB2832134 A GB 2832134A GB 2832134 A GB2832134 A GB 2832134A GB 438630 A GB438630 A GB 438630A
- Authority
- GB
- United Kingdom
- Prior art keywords
- brightness
- lamp
- strip
- aperture
- general electric
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 239000011521 glass Substances 0.000 abstract 1
- 239000000463 material Substances 0.000 abstract 1
- 229940029688 wal-dram Drugs 0.000 abstract 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J1/00—Photometry, e.g. photographic exposure meter
- G01J1/10—Photometry, e.g. photographic exposure meter by comparison with reference light or electric value provisionally void
- G01J1/12—Photometry, e.g. photographic exposure meter by comparison with reference light or electric value provisionally void using wholly visual means
- G01J1/14—Photometry, e.g. photographic exposure meter by comparison with reference light or electric value provisionally void using wholly visual means using comparison with a surface of graded brightness
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Details Of Measuring Devices (AREA)
Abstract
438,630. Photometric apparatus. GENERAL ELECTRIC CO., Ltd., Magnet House, Kingsway, London, and WALDRAM, J. M., c/o General Electric Co., Wembley, Middlesex. Oct. 3, 1934, No. 28321. [Class 97 (i)] Apparatus for measuring brightness, particularly the brightness of a distant surface such as a road, comprises a relatively large aperture through which the surface is viewed, means for illuminating a number of relatively small comparison surfaces so that they have different but known brightnesses, and means for bringing the comparison surfaces successively into apparent juxtaposition with any part of the distant surface. The comparison surfaces may be parts of a single continuous surface illuminated so that its brightness varies regularly from one point to another. As shown, the elongated viewing aperture 1 is disposed above a strip 3 of translucent material illuminated by a lamp 5 beyond one end of the strip in conjunction with an inclined diffusing reflector 4 so that the brightness of the strip varies regularly along its length. An inclined sheet 2 of clear glass behind the aperture 1 is provided with a number of small reflecting surfaces 6 enabling portions of the surface 3 to be seen. The voltage across the lamp is indicated on a meter 10 and can be controlled by a rheostat 11. A colour filter may be inserted in the path of the light from the lamp 5 to the mirrors 6.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB2832134A GB438630A (en) | 1934-10-03 | 1934-10-03 | Improvements in photometers |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB2832134A GB438630A (en) | 1934-10-03 | 1934-10-03 | Improvements in photometers |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB438630A true GB438630A (en) | 1935-11-20 |
Family
ID=10273812
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB2832134A Expired GB438630A (en) | 1934-10-03 | 1934-10-03 | Improvements in photometers |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB438630A (en) |
-
1934
- 1934-10-03 GB GB2832134A patent/GB438630A/en not_active Expired
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