GB496318A - Improvements in apparatus for ascertaining the qualitity of illumination of large surfaces such as roads - Google Patents

Improvements in apparatus for ascertaining the qualitity of illumination of large surfaces such as roads

Info

Publication number
GB496318A
GB496318A GB27626/37A GB2762637A GB496318A GB 496318 A GB496318 A GB 496318A GB 27626/37 A GB27626/37 A GB 27626/37A GB 2762637 A GB2762637 A GB 2762637A GB 496318 A GB496318 A GB 496318A
Authority
GB
United Kingdom
Prior art keywords
illumination
roads
large surfaces
eyepiece
oct
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
Application number
GB27626/37A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Koninklijke Philips NV
Original Assignee
Philips Gloeilampenfabrieken NV
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Philips Gloeilampenfabrieken NV filed Critical Philips Gloeilampenfabrieken NV
Publication of GB496318A publication Critical patent/GB496318A/en
Expired legal-status Critical Current

Links

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
    • G01J1/38—Photometry, e.g. photographic exposure meter using wholly visual means
    • G01J1/40—Photometry, e.g. photographic exposure meter using wholly visual means using limit or visibility or extinction effect

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Road Paving Structures (AREA)
  • Photometry And Measurement Of Optical Pulse Characteristics (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)

Abstract

496,318. Photometric apparatus. NAAMLOOZE VENNOOTSCHAP PHILIPS' GLOEILAMPENFABRIEKEN. Oct. 11, 1937, No. 27626. Convention date, Oct. 10, 1936. [Class 97 (i)] Apparatus for measuring the intensity of illumination of large surfaces such as roads comprises an objective 1, Fig. 1, to form an image of the surface in the plane of a transparent disc 2, Fig. 3, pivoted at 3 and carrying a row of spots 9 of graded opacities. The image is viewed through an eyepiece 4, and the disc 2 is rotated by the milled edge 8 of a brass rim to bring the various spots into the field of view in succession and to discover which is just perceptible. Preferably the objective has a large aperture and the same focal length as the eyepiece.
GB27626/37A 1936-10-10 1937-10-11 Improvements in apparatus for ascertaining the qualitity of illumination of large surfaces such as roads Expired GB496318A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL496318X 1936-10-10

Publications (1)

Publication Number Publication Date
GB496318A true GB496318A (en) 1938-11-29

Family

ID=19786733

Family Applications (1)

Application Number Title Priority Date Filing Date
GB27626/37A Expired GB496318A (en) 1936-10-10 1937-10-11 Improvements in apparatus for ascertaining the qualitity of illumination of large surfaces such as roads

Country Status (1)

Country Link
GB (1) GB496318A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2435074A (en) * 1945-06-20 1948-01-27 Nasa Contrast measuring device

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2435074A (en) * 1945-06-20 1948-01-27 Nasa Contrast measuring device

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