US3872315A - Radiation sensitive fluid analyzer - Google Patents

Radiation sensitive fluid analyzer Download PDF

Info

Publication number
US3872315A
US3872315A US42710873A US3872315A US 3872315 A US3872315 A US 3872315A US 42710873 A US42710873 A US 42710873A US 3872315 A US3872315 A US 3872315A
Authority
US
Grant status
Grant
Patent type
Prior art keywords
radiation
source
fluid
units
analyzer
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 - Lifetime
Application number
Inventor
Richard H Boll
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.)
ELSAG International BV
Original Assignee
BWX Technologies Inc
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
Grant date

Links

Images

Classifications

    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00Investigating or analysing materials by the use of optical means, i.e. using infra-red, visible or ultra-violet light
    • G01N21/17Systems in which incident light is modified in accordance with the properties of the material investigated
    • G01N21/47Scattering, i.e. diffuse reflection
    • G01N21/49Scattering, i.e. diffuse reflection within a body or fluid
    • G01N21/53Scattering, i.e. diffuse reflection within a body or fluid within a flowing fluid, e.g. smoke
    • G01N21/534Scattering, i.e. diffuse reflection within a body or fluid within a flowing fluid, e.g. smoke by measuring transmission alone, i.e. determining opacity
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00Investigating or analysing materials by the use of optical means, i.e. using infra-red, visible or ultra-violet light
    • G01N21/17Systems in which incident light is modified in accordance with the properties of the material investigated
    • G01N21/25Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
    • G01N21/255Details, e.g. use of specially adapted sources, lighting or optical systems

Abstract

An analyzer for determining the characteristic of a fluid such as, but not limited to, opacity, turbidity, the concentration of particulate matter in the fluid, the concentration of a constituent gas or liquid in a mixture of gases or liquids; comprising a pair of symetrical transmitter-receiver units each including a radiation source, and isolating window through which radiation from the source is transmitted through the fluid and the isolating window in the other of the units, each having a phototransducer adapted to receive radiation from the other unit when operating as a receiver and to receive radiation from the source in the unit after passing through the isolating window but without passing through the fluid, means for alternately and cyclically energizing the radiation source in each of the units, whereby the characteristic of the fluid computed from the output signals of the phototransducers is completely compensated for variations in the outputs of the radiation sources, input-output characteristics of the phototransducers and changes in the transparency of the isolating windows or, more specifically, for radiation source and phototransducer ageing and window fouling.

Description

Unite States atent Boll Mar. 18, 1975 RADIATION SENSITIVE FLUID ANALYZER fluid such as, but not limited to, opacity, turbidity, the [75] Inventor: Richard B0, Alliance Ohio concentration of particulate matter. in the fluid, the

concentration of a constituent gas or liquid in a mixl l Assigneei The Babcock & WilcOX mp ny, ture of gases or liquids; comprising a pair of symetrical New York, transmitter-receiver units each including a radiation 22 Filed; Dec. 21 1 Q T EJQQ EQ t TE w ndswjhr ush hish. radi on from the source is transmitted through the fluid and PP 427,108 the isolating window in the other of the units, each having a phototransducer adapted to receive radiation 521 US. Cl 250/575, 250/565, 356/207 from other, when Operating [51] Int. Cl. G0ln 21/26 to @cewe radmlon fmm, the Ource m utter [58] Field of Search 250/564, 565, 216, 573, Passmg through solatmg Wmdow but 250/574 575, 578; 356/205 208, 103, 104 mg through the fluid, means for alternately and cyclically energizing the radiation source In each of the [56] References Cited unitsc,i g heregy the charactleristt ich of hthe fluiddcompute romt e output signa s o t e p ototrans ucers UNITED STATES PATENTS is completely compensated for variations in the out- 3,6l7,756 l puts of the radiation sources input output cha acteris- 33331850 3/1972 Brggs 250/573 tics of the phototransducers and changes in the transfifif Q parency of the isolating windows or, more specifically, 5/1555 FIenniii g'iliil'lI'fl ..:11:.... 550/555 for radiation and phototransducer ageing and Primary E.Taminer-Walter Stolwein Attorney, Agent, or Firm-John F. Luhrs [57} ABSTRACT An analyzer for determining the characteristic of a sT'AcR GAS window fouling.

9 Claims, 2 Drawing Figures 32 POWE S UPPLY 66 GoNTRoL UNIT e ,l I l l l 36 34 l l 52 s oRAGE STORAGE' /54 sToRAGE STORAGE REGISTER REGISTER 62 REGISTER REGISTER 56 i l' 58 F 12 l l" 74 DIFFERENCE SUMMING DIFFERENCE AMPLIFIER AMPLIFIER AMPLIFIER INDICATOR so RECORDER CONTROLLER PATENTED 1 81575 sum 2 5 B SIDE A SIDE RADIATION SENSITIVE FLUID ANALYZER This invention relates to fluid analyzers of the type wherein a characteristic of the fluid is determined from the absorption of radiation transmitted from a source through the fluid to a phototransducer. The transmitting and receiving units of such devices are usually isolated from the fluid by means of isolating windows through which the radiation is transmitted and received. As is well known, such devices are subject to error due primarily to deterioration ofthe radiation source and phototransducer and fouling of the isolating window. Various means have been employed for compensating for such errors, such as, providing a compensating phototransducer adjacent to the radiation source and continuously or intermittently washing the faces of the isolating windows exposed to the fluid. Such expediences do not provide complete compensation for the errors as the compensating phototransducer compensates only for degradation of the radiation source and not for changes in the input-output characteristics of the phototransducers. The expediencies employed for washing the isolating windows require various forms of gadgetry such as maintaining a steady flow of air or liquid over the exposed faces of the isolating windows. Because of the insufficiencies of the compensating means presently available, analyzers of the type hereunder discussion require frequent adjustment and calibration materially limiting their application, particularly for continuous use in industrial applications.

With the foregoing in mind it is one primary objective of this invention to provide an analyzer completely self compensating for such factors as deterioration in the radiation source and phototransducer and isolating window fouling.

Further objects of the invention will be apparent from the following detailed description taken in connection with the drawings in which:

IN THE DRAWINGS FIG. 1 is a schematic illustration of an analyzer embodying the principles of my invention showing a typical in-situ application and in block diagram a typical computing circuit which may be used therewith.

FIG. 2 is a schematic illustration showing a typical application of the analyzer as a turbidimeter.

DETAILED DESCRIPTION For purposes of description I have chosen to illustrate and describe the invention in FIG. 1 as applied to the in-situ determination of the opacity of waste gases flowing through a duct or stack such as caused by particulate matter carried in suspension, water vapor and the like commonly collectively referred to as smoke. It will be recognized that the invention has a wide variety of other applications and is not limited to the in-situ analysis of waste gases; but may be used, for example, to determine a particular characteristic of a fluid whether liquid or gas and regardless of whether or not the analysis is made in-situ. Further it will be apparent that the invention may be used to determine a particular characteristic of fluids produced for use in industrial processes to aid in maximizing the efficiency of production or to aid in maintaining the characteristic at, or below, or above some predetermined value.

Referring to FIG. 1 there is shown a duct or stack 2 through which waste gases flow in the direction of the arrow, having sides, identified for convenience as the A side and the B side. Mounted on the A side is a transmitter-receiver unit generally indicated at 4 and a symetrical transmitter-receiver unit generally indicated at 6 mounted on the B side.

In the following description components incorporated in the transmitter-receiver unit 4 are identified by a numeral followed by a letter A, whereas similar components in the transmitter-receiver unit 6 are identified by the same numeral followed by the letter B.

Incorporated in the transmitter-receiver 4 is a radiation source, such as a lamp 8A, radiation from which during the half cycle of operation, when the unit is operating as a transmitter, (as indicated by the dashed line directional) passes through a beamsplitter 10A, through a V-shaped window 12A, the stack gases present in duct 2, V-shaped window 128 and is reflected by beamsplitter 10B onto a phototransducer 228. Also during this half cycle of operation radiation from lamp 8A is diverted by beamsplitter 10A, to a mirror 14A, thence to a mirror 16A, through window 12A to a mirror 18A, thence to a beamsplitter 20A and thence to a phototransducer 22A.

During the half cycle of operation when the unit 6 is operating as a transmitter the operation is reversed. As shown by the solid directional line, radiation from source 88, passes through beamsplitter 108, through V-shaped window 128, the stack gases present in duct 2, V-shaped window 12A and is reflected by beamsplitter 10A onto phototransducer 22A. Radiation from source 83 is diverted by beamsplitter 108 to a mirror 14B, thence to a mirror 168, through window 12B to a mirror 18B, thence to a beamsplitter 20B and thence to phototransducer 22B.

As is evident from the following equations l through (9), from the output signals of phototransducers 22A and 22B during one complete cycle of operation the turbidity, or smoke concentration, in the stack gases may be computed:

When a side transmitter-receiver unit 4 is a transmitter 10 AMA WA2I10 s, BM W,,W,,1 e Y L Where:

S output signal from phototransducer 22A A sensitivity factor of phototransducer 22A M mirror transmission factor including the characteristics of mirrors 14A, 16A and 18A as well as beamsplitters 10A and 20A W,, transmission factor of window 12A 1 radiation intensity of source 8A S, output signal of phototransducer 22B B sensitivity factor of phototransducer 22B M mirror transmission factor which includes the characteristics of beamsplitters 10A, 10B and 208 W transmission factor of window 12B 7 specific turbidity of the flue gases L en ths? E 9 ad t .nna hth qu ,4 2

When B side transmitter-receiver unit 6 is a transmitter 2 AME, A B m) e y L 20 BMB B 20 Where:

S output signal from phototransducer 22A M mirror transmission factor including the char- 1/ (MAI/MB) (WE/WA) e y L 2/ a a) (WA/W8) e y L and multiplying equations (5) and (6):

( i/ 10) (S2/S20) (MAI/MA) (MEI/MB) e 2 y L Taking natural logarithms of both sides of equation (7) In I/ 10) In 2/ 20) In A A) and rearranging:

thus the turbidity is obtained completely independent of the window transmission factors, W A and W independent of the phototransducer sensitivities, A and B and independent of the lamp intensities, I and I Moreover the third term on the right hand side of equation (9) is a constant whose value will remain fixed over long periods of time inasmuch as the transmitterreceiver units may readily be constructed so as to substantially hermetically seal the interior of the units from ambient conditions. I

Shown in FIG. 1 is one form of computing circuit which may be used to automatically compute either the total or specific turbidity ('yL) or (y) from the output signals 5,, S S and S The radiation sources 8A and 8B are connected to a power supply and control unit 32 which during one-half cycle of operation energizes the source 8A and during the other one-half cycle energizes the source 8B. During the half-cycle when source 8A is energized phototransducers 22A and 22B generate output signals S and S respectively. During the alternate half-cycle when source 8B is energized phototransducers 22A and 22B generate output signals S and S respectively. As the sources 22A and 22B are energized control impulses are simultaneously sent along lines 34, 36 from the power supply and control unit 32 indicating the source energized.

The signals generated by phototransducer 22A input to a logarithmic amplifier 46, whereas the signals gen- 4 erated by phototransducer 22B input to a logarithmic amplifier 48. The output signals from logarithmic amplifier 46 are applied along line 50 to storage registers 52 and 54. The registers 52 and 54 are connected through lines 56, 58 respectively to a difference amplifier 60 connected to an algebraic summing amplifier 62 by way of line 64. The output signals from logarithmic amplifier 48 are applied along the line 66 to storage registers 68 and 70. Registers 68 and 70 are also connected to the power supply and control unit 32 through lines 36 and 34 respectively. The registers 68 and 70 are connected through lines 72 and 74 respectively to a difference amplifier 76, connected to algebraic summing amplifier 62 by way of line 78. The output signal from algebraic summing amplifier 62 may be transmitted to an indicating, recording and/or controlling device such as shown at 80. The algebraic summing amplifier 62 may be provided with a calibration input 82 which may be used to adjust for the third term on the right hand side of equation (9), which heretofor has been related to be a constant whose value will remain fixed over long periods of time.

After one complete cycle of operation the logarithms of the values of unabsorbed radiation from radiation sources 8A and 8B are stored in registers 52 and 70, and the values of the logarithms of absorbed radiation from radiation sources 8A and 8B are stored in registers 68 and 54. The registers 52, 54 provide the inputs to the difference amplifier 60, while the registers 68, 70 provide the inputs to the difference amplifier 76. The outputs of the amplifiers 60, 76 provide the inputs to the summing amplifier 62. The amplifier 62 thus provides an output signal along line 84 that is in functional relationship to the turbidity of the flue gases.

It is apparent that the radiation sources 8A and 8B may be selected to emit predominantly radiation having a wave length compatible with the fluid characteristic to be determined. Thus, for example, depending upon the fluid characteristic to be determined the sources could be incandescent, hollow cathode or mercury arc lamps. When used as a smoke detector radiation sources having wave length characteristics close to those of the human eye could be selected so that the analyzer would indicate a smoke opacity approximating that determined by an observer. The transmitted wave length band can be, if desired, further defined by optical filters such as shown at 24A and 24B.

Collimating lenses such as shown at 26A, 26B would normally be employed to produce a radiation beam of substantially parallel rays. Similarly, well known expediencies may be incorporated in the transmitterreceiver units such as the lens-pinhole arrangement comprising lenses 28A, 28B and pinholes 30A and 30B disposed at the focal points of the lenses to limit the viewing angles of the associated phototransducers.

Referring to FIG. 2, there is shown a fluid sampler 88, which may be a container if a static fluid sample is being analyzed, or a pipe or duct. if a flowing fluid is being analyzed in-situ. Secured to the wall of the sampler 88 at an angle 0 to each other (usually 90), are transmitter-receiver units 4 and 6 with the windows 12A and 12B exposed to the sampled fluid through suitable openings in sampler 88. When the unit 4 is operating as a transmitter, the unit 6 receives scattered light from the sampled fluid and vice versa. The turbidity of the fluid and then be determined from the output signals of phototransducers 22A and 22B.

When the analyzer is arranged as a scattered light turbidimeter (rather than as a transmitted light opacity meter) equations (2) and (3) do not apply. The factor e 7 L would be replaced by a function of turbidity, which may be designated at f('y). In this case, logarithmic processing would produce an output that, in general, is not linear to specific turbidity, but is usually proportional to I n Thus, if desirable, the computing circuit described above may be arranged to generate an output signal proportional to f (y) in accordance with the following equation. fly) [M M /M iz'l l i 2 From the foregoing description it is apparent, regardless of whether the analyzer is applied as a transmitted light opacity meter or as a scattered light turbidimeter, the advantages of freedom from errors due to window fouling, lamp ageing, or phototransducer ageing are obtained.

While in the foregoing description a specific optical system has been illustrated and described, it is evident that alternate optical systems may be used which have in common the fact that the transmitter-receiver units can function either as a transmitter or receiver, and when functioning as a transmitter, radiation source intensity, changes in window transparency and phototransducer sensitivity are monitored by the phototransducer.

I claim:

1. In an analyzer for determining a characteristic of a fluid, in combination, a pair of symetrical transmitterreceiver units each comprising a housing, a radiation source disposed within said housing, an opening in one wall of said housing, a window closing said opening and forming a cavity having transparent walls through which radiation from the source is transmitted through the fluid to the other of the units, a phototransducer disposed within the housing, means diverting radiation from the source through the window to the phototransducer without passing through the fluid between said units, and means directing radiation received through the fluid from the other of said units through said window to said phototrandsucer, the combination further comprising means for alternately and cyclically energizing the radiation source in each of said units to cause each of said units to cyclically and alternately act as a transmitter and then as a receiver whereby the phototransducer receives radiation from the radiation source in the unit when operating as a transmitter and from the radiation source in the other of said units when operating as a receiver.

2. In an analyzer as set forth in claim 1 further includ- 6 ing a computing circuit responsive tothe signals generated by said phototransducers generating an output signal corresponding to the characteristic of the fluid.

3. In an analyzer as set forth in claim 1 wherein the means diverting radiation from the source through the window without passing through the fluid between said units comprises a first beamsplitter disposed in the path of the radiation from the source to the window, an optical system directing the diverted radiation through the window onto a second beamsplitter directing the diverted radiation onto the phototransducer.

4. An analyzer as set forth in claim 3 wherein said first beamsplitter also acts as a reflector to direct radiation received from the other of said units onto said phototransducer.

5. An analyzer as set forth in claim 4 further including a lens and pinhole located between the second beamsplitter and phototransducer, said pinhole located at the focal point of said lens.

6. An analyzer as set forth in claim 4 wherein the radiation received from the other of said units after being reflected by said first beamsplitter passes through said second beamsplitter before striking said. phototransducer.

7. An analyzer as set forth in claim 2 wherein the computing circuit includes means for algebraically adding the logarithms of the signals generated by said phototransducers to thereby produce an output signal proportional to the opacity of the fluid.

8. An analyzer as set forth in claim 2 wherein said transmitter-receiver units are disposed at substantially right angles whereby each receives scattered light from the other unit when operating as a receiver, and said computing circuit comprises means generating an output signal varying in functional relationship to the signals generated by said phototransducers to thereby produce an output signal proportional to the turbidity of the fluid.

9. A analyzer as set forth in claim 3 wherein said first beamsplitter diverts radiation from the source in a direction at right angles to the radiation from said source, and said optical system comprises a first mirror directing the diverted radiation in a direction parallel to the radiation from said source, a second mirror then directing said diverted radiation in reverse direction but parallel to the radiation diverted by said first beamsplitter through said window onto a third mirror directing the diverted radiation in reverse direction but parallel to the radiation from said source onto said second beamsplitter.

Claims (9)

1. In an analyzer for determining a characteristic of a fluid, in combination, a pair of symetrical transmitter-receiver units each comprising a housing, a radiation source disposed within said housing, an opening in one wall of said housing, a window closing said opening and forming a cavity having transparent walls through which radiation from the source is transmitted through the fluid to the other of the units, a phototransducer disposed within the housing, means diverting radiation from the source through the window to the phototransducer without passing through the fluid between said units, and means directing radiation received through the fluid from the other of said units through said window to said phototrandsucer, the combination further comprising means for alternately and cyclically energizing the radiation source in each of said units to cause each of said units to cyclically and alternately act as a transmitter and then as a receiver whereby the phototransducer receives radiation from the radiation source in the unit when operating as a transmitter and from the radiation source in the other of said units when operating as a receiver.
2. In an analyzer as set forth in claim 1 further including a computing circuit responsive to the signals generated by said phototransducers generating an output signal corresponding to the characteristic of the fluid.
3. In an analyzer as set forth in claim 1 wherein the means diverting radiation from the source through the window without passing through the fluid between said units comprises a first beamsplitter disposed in the path of the radiation from the source to the window, an optical system directing the diverted radiation through the window onto a second beamsplitter directing the diverted radiation onto the phototransducer.
4. An analyzer as set forth in claim 3 wherein said first beamsplitter also acts as a reflector to direct radiation received from the other of said units onto said phototransducer.
5. An analyzer as set forth in claim 4 further including a lens and pinhole located between the second beamsplitter and phototransducer, said pinhole located at the focal point of said lens.
6. An analyzer as set forth in claim 4 wherein the radiation received from the other of said units after being reflected by said first beamsplitter passes through said second beamsplitter before striking said phototransducer.
7. An analyzer as set forth in claim 2 wherein the computing circuit includes means for algebraically adding the logarithms of the signals generated by said phototransducers to thereby produce an output signal proportional to the opacity of the fluid.
8. An analyzer as set forth in claim 2 wherein said transmitter-receiver units are disposed at substantially right angles whereby each receives scattered light from the other unit when operating as a receiver, and said computing circuit comprises means generating an output signal varying in functional relationship to the signals generated by said phototransducers to thereby produce an output signal proportional to the turbidity of the fluid.
9. A analyzer as set forth in claim 3 wherein said first beamsplitter diverts radiation from the source in a direction at right angles to the radiAtion from said source, and said optical system comprises a first mirror directing the diverted radiation in a direction parallel to the radiation from said source, a second mirror then directing said diverted radiation in reverse direction but parallel to the radiation diverted by said first beamsplitter through said window onto a third mirror directing the diverted radiation in reverse direction but parallel to the radiation from said source onto said second beamsplitter.
US3872315A 1973-12-21 1973-12-21 Radiation sensitive fluid analyzer Expired - Lifetime US3872315A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US3872315A US3872315A (en) 1973-12-21 1973-12-21 Radiation sensitive fluid analyzer

Applications Claiming Priority (7)

Application Number Priority Date Filing Date Title
US3872315A US3872315A (en) 1973-12-21 1973-12-21 Radiation sensitive fluid analyzer
CA 211419 CA1017165A (en) 1973-12-21 1974-10-15 Compensated fluid analyzer using two transmitter-receiver units
GB5436974A GB1485428A (en) 1973-12-21 1974-12-17 Fluid analysers
FR7442172A FR2255594B1 (en) 1973-12-21 1974-12-20
DE19742460434 DE2460434A1 (en) 1973-12-21 1974-12-20 Flud-analyzer
ES433194A ES433194A1 (en) 1973-12-21 1974-12-20 A fluid analyzer apparatus.
JP14633874A JPS5847657B2 (en) 1973-12-21 1974-12-21

Publications (1)

Publication Number Publication Date
US3872315A true US3872315A (en) 1975-03-18

Family

ID=23693520

Family Applications (1)

Application Number Title Priority Date Filing Date
US3872315A Expired - Lifetime US3872315A (en) 1973-12-21 1973-12-21 Radiation sensitive fluid analyzer

Country Status (7)

Country Link
US (1) US3872315A (en)
JP (1) JPS5847657B2 (en)
CA (1) CA1017165A (en)
DE (1) DE2460434A1 (en)
ES (1) ES433194A1 (en)
FR (1) FR2255594B1 (en)
GB (1) GB1485428A (en)

Cited By (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3994603A (en) * 1974-03-08 1976-11-30 Cerberus Ag Detection system to determine the transmissivity of a medium with respect to radiation, particularly the light transmissivity of smoke-contaminated air, for fire detection
US4146799A (en) * 1976-10-29 1979-03-27 Itt Industries, Inc. Oil concentration detector
US4317113A (en) * 1979-08-24 1982-02-23 Hochiki Corporation Photoelectric smoke sensor
DE3212734A1 (en) * 1981-04-28 1983-01-13 Itt Ind Gmbh Deutsche A method for measurement and determination of oil in water and arrangement for performing the method
US4560874A (en) * 1981-06-02 1985-12-24 Santa Barbara Research Center Reference channel for sensing optical contamination
US4647777A (en) * 1985-05-31 1987-03-03 Ametrek, Inc. Selective gas detector
FR2593912A1 (en) * 1986-02-04 1987-08-07 Vaisala Oy Method for measuring the transmittance of light and apparatus for implementing such process
US4726684A (en) * 1983-07-22 1988-02-23 Oki Electric Industry Co., Ltd. Measurement apparatus for optical transmission factor
EP0262911A2 (en) * 1986-09-29 1988-04-06 Circuits And Systems, Inc. System for transmission loss comparison
EP0298584A2 (en) * 1987-05-13 1989-01-11 Combustion Developments Limited Monitoring equipment using transmitted light
US4814628A (en) * 1987-03-20 1989-03-21 Precitronic Gesellschaft Fuer Feinmechanik Und Electronic Mbh Arrangement for the transmission of laser light with reference source for backscatter obstruction detection
US4838698A (en) * 1986-04-07 1989-06-13 Hochiki Corp. Extinction type detector
US5245200A (en) * 1989-07-10 1993-09-14 Fladda Gerdt H Apparatus and method for preventing blockage of a measuring head for effecting measurements of suspended substances
US5325171A (en) * 1991-09-20 1994-06-28 Nec Corporation System for calibration of optical instrument on satellite with reference light source
US5477328A (en) * 1993-04-27 1995-12-19 Oki Electric Industry Co., Ltd. Optical transmission calibration device and method for optical transmissiometer
US5517314A (en) * 1991-12-04 1996-05-14 Opsis Ab Optical analysing equipment for determining parameters of gaseous substances flowing through a duct
US5610713A (en) * 1995-05-31 1997-03-11 Jenoptik Ag Device for measuring the optical range of optical and electronics systems
WO1997029358A1 (en) * 1996-02-12 1997-08-14 Shell Internationale Research Maatschappij B.V. Self-correcting spectroscopic process analysis
US6117682A (en) * 1993-04-27 2000-09-12 Dexsil Corporation Method for detecting hydrocarbons in water
GB2384555A (en) * 2001-01-16 2003-07-30 Teraview Ltd Apparatus and method for investigating a sample
US20040063154A1 (en) * 2002-08-23 2004-04-01 Booth David K. Rapidly responding, false detection immune alarm signal producing smoke detector
US20060261967A1 (en) * 2002-08-23 2006-11-23 Marman Douglas H Smoke detector and method of detecting smoke
US9322773B2 (en) 2011-06-07 2016-04-26 Measurement Specialties, Inc. Optical sensing device for fluid sensing and methods therefor

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3617756A (en) * 1968-03-26 1971-11-02 Erwin Sick Optical measuring apparatus using measuring and comparison light beams
US3652850A (en) * 1969-05-22 1972-03-28 Nat Res Dev Measurement of optical density
US3659946A (en) * 1969-12-10 1972-05-02 Shimadzu Corp Automated light scattering photometer
US3677652A (en) * 1971-06-15 1972-07-18 Gte Sylvania Inc Fluid analyzer apparatus
US3809912A (en) * 1971-06-29 1974-05-07 Plessey Handel Investment Ag Light scattering measurement instrument

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3617756A (en) * 1968-03-26 1971-11-02 Erwin Sick Optical measuring apparatus using measuring and comparison light beams
US3652850A (en) * 1969-05-22 1972-03-28 Nat Res Dev Measurement of optical density
US3659946A (en) * 1969-12-10 1972-05-02 Shimadzu Corp Automated light scattering photometer
US3677652A (en) * 1971-06-15 1972-07-18 Gte Sylvania Inc Fluid analyzer apparatus
US3809912A (en) * 1971-06-29 1974-05-07 Plessey Handel Investment Ag Light scattering measurement instrument

Cited By (33)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3994603A (en) * 1974-03-08 1976-11-30 Cerberus Ag Detection system to determine the transmissivity of a medium with respect to radiation, particularly the light transmissivity of smoke-contaminated air, for fire detection
US4146799A (en) * 1976-10-29 1979-03-27 Itt Industries, Inc. Oil concentration detector
US4317113A (en) * 1979-08-24 1982-02-23 Hochiki Corporation Photoelectric smoke sensor
DE3212734A1 (en) * 1981-04-28 1983-01-13 Itt Ind Gmbh Deutsche A method for measurement and determination of oil in water and arrangement for performing the method
US4560874A (en) * 1981-06-02 1985-12-24 Santa Barbara Research Center Reference channel for sensing optical contamination
US4726684A (en) * 1983-07-22 1988-02-23 Oki Electric Industry Co., Ltd. Measurement apparatus for optical transmission factor
US4647777A (en) * 1985-05-31 1987-03-03 Ametrek, Inc. Selective gas detector
FR2593912A1 (en) * 1986-02-04 1987-08-07 Vaisala Oy Method for measuring the transmittance of light and apparatus for implementing such process
US4838698A (en) * 1986-04-07 1989-06-13 Hochiki Corp. Extinction type detector
EP0262911A3 (en) * 1986-09-29 1989-08-23 Circuits And Systems, Inc. System for transmission loss comparison
EP0262911A2 (en) * 1986-09-29 1988-04-06 Circuits And Systems, Inc. System for transmission loss comparison
US4814628A (en) * 1987-03-20 1989-03-21 Precitronic Gesellschaft Fuer Feinmechanik Und Electronic Mbh Arrangement for the transmission of laser light with reference source for backscatter obstruction detection
EP0298584A2 (en) * 1987-05-13 1989-01-11 Combustion Developments Limited Monitoring equipment using transmitted light
EP0298584A3 (en) * 1987-05-13 1990-06-27 Combustion Developments Limited Monitoring equipment using transmitted light
US5245200A (en) * 1989-07-10 1993-09-14 Fladda Gerdt H Apparatus and method for preventing blockage of a measuring head for effecting measurements of suspended substances
US5325171A (en) * 1991-09-20 1994-06-28 Nec Corporation System for calibration of optical instrument on satellite with reference light source
US5517314A (en) * 1991-12-04 1996-05-14 Opsis Ab Optical analysing equipment for determining parameters of gaseous substances flowing through a duct
US6117682A (en) * 1993-04-27 2000-09-12 Dexsil Corporation Method for detecting hydrocarbons in water
US5477328A (en) * 1993-04-27 1995-12-19 Oki Electric Industry Co., Ltd. Optical transmission calibration device and method for optical transmissiometer
US5610713A (en) * 1995-05-31 1997-03-11 Jenoptik Ag Device for measuring the optical range of optical and electronics systems
EP0745838B1 (en) * 1995-05-31 2003-02-05 Vaisala Impulsphysik GmbH Visual range measuring device
WO1997029358A1 (en) * 1996-02-12 1997-08-14 Shell Internationale Research Maatschappij B.V. Self-correcting spectroscopic process analysis
GB2384555A (en) * 2001-01-16 2003-07-30 Teraview Ltd Apparatus and method for investigating a sample
US7214940B2 (en) 2001-01-16 2007-05-08 Teraview Limited Apparatus and method for investigating a sample
US20040065832A1 (en) * 2001-01-16 2004-04-08 Cluff Julian Alexander Apparatus and method for investigating a sample
GB2384555B (en) * 2001-01-16 2005-05-04 Teraview Ltd Apparatus and method for investigating a sample
US7075445B2 (en) 2002-08-23 2006-07-11 Ge Security, Inc. Rapidly responding, false detection immune alarm signal producing smoke detector
US20060261967A1 (en) * 2002-08-23 2006-11-23 Marman Douglas H Smoke detector and method of detecting smoke
US20040063154A1 (en) * 2002-08-23 2004-04-01 Booth David K. Rapidly responding, false detection immune alarm signal producing smoke detector
US7564365B2 (en) 2002-08-23 2009-07-21 Ge Security, Inc. Smoke detector and method of detecting smoke
US9322773B2 (en) 2011-06-07 2016-04-26 Measurement Specialties, Inc. Optical sensing device for fluid sensing and methods therefor
US9851295B2 (en) 2011-06-07 2017-12-26 Measurement Specialties, Inc. Optical devices for fluid sensing and methods therefor
US9964483B2 (en) 2011-06-07 2018-05-08 Measurement Specialties, Inc. Low-temperature safe sensor package and fluid properties sensor

Also Published As

Publication number Publication date Type
CA1017165A (en) 1977-09-13 grant
ES433194A1 (en) 1976-12-01 application
DE2460434A1 (en) 1975-08-14 application
JPS5098886A (en) 1975-08-06 application
FR2255594A1 (en) 1975-07-18 application
FR2255594B1 (en) 1978-09-29 grant
GB1485428A (en) 1977-09-14 application
CA1017165A1 (en) grant
JPS5847657B2 (en) 1983-10-24 grant

Similar Documents

Publication Publication Date Title
US3508830A (en) Apparatus for light scattering measurements
US3335285A (en) Photoelectric system for detecting objects in a zone including vibrating light source
US4577110A (en) Optical apparatus and method for measuring the characteristics of materials by their fluorescence
US4201916A (en) Ultraviolet radiation sensor for use in liquid purification system
US6396056B1 (en) Gas detectors and gas analyzers utilizing spectral absorption
US2237193A (en) Detection of objects by electromagnetic rays
US4730922A (en) Absorbance, turbidimetric, fluorescence and nephelometric photometer
US4649711A (en) Apparatus and method for infrared optical electronic qualitative analysis of a fluid independent of the temperature thereof
Proffitt et al. Fast‐response dual‐beam UV‐absorption ozone photometer suitable for use on stratospheric balloons
US4560873A (en) Situ multi-channel combustion gas analyzer
US3488491A (en) Filter techniques for gas analyzers employing an inert gas to pressure broaden the absorption spectrum of gas being detected
US5807750A (en) Optical substance analyzer and data processor
US5340987A (en) Apparatus and method for analyzing gas
US4694173A (en) Nondispersive gas analyzer having no moving parts
US3714444A (en) Suspended solids analyzer
Williams et al. Molecular correlation spectrometry
US4560875A (en) Infrared absorption gas detector
US6130439A (en) Instrument for measuring the refractive index of a fluid
US4420256A (en) Dust measurement
US4753530A (en) Analytical optical instruments
US4516856A (en) Optical apparatus for fluorescence polarization instrument
US3588496A (en) Radiation analysis apparatus having an absorption chamber with partially reflective mirror surfaces
US3941487A (en) Colorimetric fluid analyzer
US3428401A (en) Flame photometer
US3853407A (en) Multiple path spectrophotometer method and apparatus

Legal Events

Date Code Title Description
AS Assignment

Owner name: BABCOCK & WILCOX TRACY POWER, INC., A CORP. OF DE,

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:BABCOCK & WILCOX COMPANY, THE, A CORP. OF DE;REEL/FRAME:005161/0198

Effective date: 19890831

AS Assignment

Owner name: ELSAG INTERNATIONAL B.V., A CORP. OF THE NETHERLAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:BABCOCK & WILCOX TRACY POWER, INC., A CORP. OF DE;REEL/FRAME:005238/0432

Effective date: 19891031