GB689856A - Improvements in or relating to densitometers - Google Patents
Improvements in or relating to densitometersInfo
- Publication number
- GB689856A GB689856A GB2594150A GB2594150A GB689856A GB 689856 A GB689856 A GB 689856A GB 2594150 A GB2594150 A GB 2594150A GB 2594150 A GB2594150 A GB 2594150A GB 689856 A GB689856 A GB 689856A
- Authority
- GB
- United Kingdom
- Prior art keywords
- pulses
- frequency
- circuit
- output
- light
- 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
- 230000005540 biological transmission Effects 0.000 abstract 1
- 239000011022 opal Substances 0.000 abstract 1
- 230000003287 optical effect Effects 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
- G01J1/20—Photometry, e.g. photographic exposure meter by comparison with reference light or electric value provisionally void intensity of the measured or reference value being varied to equalise their effects at the detectors, e.g. by varying incidence angle
- G01J1/22—Photometry, e.g. photographic exposure meter by comparison with reference light or electric value provisionally void intensity of the measured or reference value being varied to equalise their effects at the detectors, e.g. by varying incidence angle using a variable element in the light-path, e.g. filter, polarising means
- G01J1/24—Photometry, e.g. photographic exposure meter by comparison with reference light or electric value provisionally void intensity of the measured or reference value being varied to equalise their effects at the detectors, e.g. by varying incidence angle using a variable element in the light-path, e.g. filter, polarising means using electric radiation detectors
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Investigating Or Analysing Materials By Optical Means (AREA)
Abstract
689,856. Photo-electric densitometers. NATIONAL RESEARCH DEVELOPMENT CORPORATION. Jan. 25, 1952 [Oct. 25, 1950], No. 25941/50. Class 40 (iii). In a transmission densitometer two interlaced sets of light pulses are received by a lightsensitive cell, the electrical output of which is metered at the fundamental frequency of one of the sets of pulses so that when balance between the pulses is obtained by adjusting the test beam the fundamental frequency does not appear, the position of the adjusting means then being an indication of sample density. As shown, light from a source 1 forms a comparison beam S and a test beam T. The beams are chopped alternately by means of a motor-driven slotted cylinder 2 surrounding the light source. Beam T is focused on an opal screen, diffused light from which passes through the sample 6 and an adjustable optical wedge 7 to a photo-multiplier tube 8. Beam S also reaches tube 8 by way of mirrors M1, M2 and a spherical mirror 9 and an adjustable diaphragm 10 and wedge 11. The output of the multiplier tube is amplified on an amplifier sensitive to the frequency of each set of pulses. Then when balance occurs between the two beams this frequency disappears and the amplifier receives light pulses of double the frequency, to which it does not respond. Balance is indicated by a meter M. Circuit (Fig. 2).-The output of the photomultiplier tube 8 is fed through three stages of resistance-capacity coupled amplifiers consisting of the left-hand side of double triode V1 and pentodes V2 and V3. The amplifier is made sensitive to the frequency of one of the train of pulses by a high Q tuned circuit in the anode circuit of valve V1 and by a parallel-T resistancecapacity network RC connected in the anode to grid feed-back circuit of valve V2. The output of valve V3 is indicated on a meter M through a full-wave rectifier circuit. Initially the comparison beam is blanked off, and a film of standard transmissivity is inserted.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB2594150A GB689856A (en) | 1950-10-25 | 1950-10-25 | Improvements in or relating to densitometers |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB2594150A GB689856A (en) | 1950-10-25 | 1950-10-25 | Improvements in or relating to densitometers |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB689856A true GB689856A (en) | 1953-04-08 |
Family
ID=10235804
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB2594150A Expired GB689856A (en) | 1950-10-25 | 1950-10-25 | Improvements in or relating to densitometers |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB689856A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3292484A (en) * | 1961-12-21 | 1966-12-20 | Rca Corp | Apparatus for monitoring spectral characteristics of substances |
| US4832490A (en) * | 1986-08-11 | 1989-05-23 | Leybold-Heraeus Gmbh | Photometer |
-
1950
- 1950-10-25 GB GB2594150A patent/GB689856A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3292484A (en) * | 1961-12-21 | 1966-12-20 | Rca Corp | Apparatus for monitoring spectral characteristics of substances |
| US4832490A (en) * | 1986-08-11 | 1989-05-23 | Leybold-Heraeus Gmbh | Photometer |
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