GB1168483A - Backscatter Fog Measuring Instrument - Google Patents

Backscatter Fog Measuring Instrument

Info

Publication number
GB1168483A
GB1168483A GB4384766A GB4384766A GB1168483A GB 1168483 A GB1168483 A GB 1168483A GB 4384766 A GB4384766 A GB 4384766A GB 4384766 A GB4384766 A GB 4384766A GB 1168483 A GB1168483 A GB 1168483A
Authority
GB
United Kingdom
Prior art keywords
transistor
conduct
transistors
switch
capacitor
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
GB4384766A
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.)
Hoffman Electronics Corp
Original Assignee
Hoffman Electronics Corp
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 Hoffman Electronics Corp filed Critical Hoffman Electronics Corp
Publication of GB1168483A publication Critical patent/GB1168483A/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
    • G01N21/47—Scattering, i.e. diffuse reflection
    • G01N21/49—Scattering, i.e. diffuse reflection within a body or fluid
    • G01N21/53—Scattering, i.e. diffuse reflection within a body or fluid within a flowing fluid, e.g. smoke
    • G01N21/538—Scattering, i.e. diffuse reflection within a body or fluid within a flowing fluid, e.g. smoke for determining atmospheric attenuation and visibility

Landscapes

  • General Health & Medical Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)
  • Burglar Alarm Systems (AREA)
  • Measurement Of Velocity Or Position Using Acoustic Or Ultrasonic Waves (AREA)

Abstract

1,168,483. Transistor time delay circuits. HOFFMAN ELECTRONICS CORP. 30 Sept., 1966 [30 Sept., 1965], No. 43847/66. Heading H3T. [Also in Division G1] A photo-electric fog detector (see Division G1 operates a device in which the switch-on and switch-off are delayed. In the delay circuit the signal from a phase-sensitive rectifier 41 which is positive in foggy conditions is applied to a transistor 78 which conducts when the signal is at all positive, the base/emitter voltage being offset by a diode 79 with an equal forward voltage drop. Conduction of 78 cuts off a transistor 85 allowing the capacitor 87 of a first delay circuit to charge. After a predetermined delay transistors 88, 95 and 100 conduct and through transistors 108, 109 111, 117, 118, 127 and 130 switch on a driver transistor 131 to supply current to an alarm relay. When foggy conditions cease, 78 cuts off, switching on 85. This discharges the capacitor 87, cutting off 88, 95 and 100 without delay. The conduction of transistors 108 and 109 is delayed until capacitor 115 has discharged sufficiently through resistors 103, 102, 101 and 114, which may take several minutes. When 108 and 109 conduct, 117 is cut off and 118, 127 and 130 conduct with the result that 131 is cut off and the relay deenergized.
GB4384766A 1965-09-30 1966-09-30 Backscatter Fog Measuring Instrument Expired GB1168483A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US49165865A 1965-09-30 1965-09-30

Publications (1)

Publication Number Publication Date
GB1168483A true GB1168483A (en) 1969-10-29

Family

ID=23953108

Family Applications (1)

Application Number Title Priority Date Filing Date
GB4384766A Expired GB1168483A (en) 1965-09-30 1966-09-30 Backscatter Fog Measuring Instrument

Country Status (2)

Country Link
DE (1) DE1573207A1 (en)
GB (1) GB1168483A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2619919A1 (en) * 1987-09-01 1989-03-03 Jaeger Device for measuring visibility in a turbid medium
FR2626076A1 (en) * 1988-01-19 1989-07-21 France Etat Device intended for detecting variations in transparency of an atmosphere to be monitored

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2594557B1 (en) * 1986-02-17 1988-06-10 Jaeger DEVICE FOR DETECTING FOREIGN SUBSTANCES THROUGH A WALL AND DRIVING ASSISTANCE SYSTEM FOR VEHICLES OR AIRCRAFT
EP0208610B1 (en) * 1985-07-04 1990-11-22 Jaeger Device for detection of foreign substances through a wall and aid-system for driving vehicles or aircrafts

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2619919A1 (en) * 1987-09-01 1989-03-03 Jaeger Device for measuring visibility in a turbid medium
FR2626076A1 (en) * 1988-01-19 1989-07-21 France Etat Device intended for detecting variations in transparency of an atmosphere to be monitored

Also Published As

Publication number Publication date
DE1573207A1 (en) 1970-05-21

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Legal Events

Date Code Title Description
PS Patent sealed