CA1136882A - Spectrophotometric apparatus for remote measuring - Google Patents
Spectrophotometric apparatus for remote measuringInfo
- Publication number
- CA1136882A CA1136882A CA000344463A CA344463A CA1136882A CA 1136882 A CA1136882 A CA 1136882A CA 000344463 A CA000344463 A CA 000344463A CA 344463 A CA344463 A CA 344463A CA 1136882 A CA1136882 A CA 1136882A
- Authority
- CA
- Canada
- Prior art keywords
- measuring
- optical
- fibre optic
- loop
- light beam
- 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
- 239000000835 fiber Substances 0.000 claims abstract description 71
- 230000003287 optical effect Effects 0.000 claims abstract description 67
- 239000000243 solution Substances 0.000 claims description 36
- 230000001681 protective effect Effects 0.000 claims description 11
- 230000002285 radioactive effect Effects 0.000 claims description 8
- 230000005855 radiation Effects 0.000 claims description 6
- 230000000694 effects Effects 0.000 claims description 5
- 230000004048 modification Effects 0.000 claims description 4
- 238000012986 modification Methods 0.000 claims description 4
- 230000000149 penetrating effect Effects 0.000 claims description 4
- 239000012088 reference solution Substances 0.000 claims description 2
- 230000001360 synchronised effect Effects 0.000 claims 1
- 230000006870 function Effects 0.000 description 12
- 238000005259 measurement Methods 0.000 description 6
- 238000004458 analytical method Methods 0.000 description 5
- 230000005540 biological transmission Effects 0.000 description 5
- 238000010521 absorption reaction Methods 0.000 description 4
- 238000002798 spectrophotometry method Methods 0.000 description 4
- 229910002651 NO3 Inorganic materials 0.000 description 3
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 3
- 235000013405 beer Nutrition 0.000 description 3
- 230000000875 corresponding effect Effects 0.000 description 3
- QEFYFXOXNSNQGX-UHFFFAOYSA-N neodymium atom Chemical compound [Nd] QEFYFXOXNSNQGX-UHFFFAOYSA-N 0.000 description 3
- 239000000523 sample Substances 0.000 description 3
- 230000035945 sensitivity Effects 0.000 description 3
- 230000003595 spectral effect Effects 0.000 description 3
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000007246 mechanism Effects 0.000 description 2
- 229910017604 nitric acid Inorganic materials 0.000 description 2
- 229910052781 Neptunium Inorganic materials 0.000 description 1
- 229910052778 Plutonium Inorganic materials 0.000 description 1
- 229910052770 Uranium Inorganic materials 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 230000001678 irradiating effect Effects 0.000 description 1
- 230000031700 light absorption Effects 0.000 description 1
- LFNLGNPSGWYGGD-UHFFFAOYSA-N neptunium atom Chemical compound [Np] LFNLGNPSGWYGGD-UHFFFAOYSA-N 0.000 description 1
- 238000005375 photometry Methods 0.000 description 1
- OYEHPCDNVJXUIW-UHFFFAOYSA-N plutonium atom Chemical compound [Pu] OYEHPCDNVJXUIW-UHFFFAOYSA-N 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 238000010183 spectrum analysis Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- JFALSRSLKYAFGM-UHFFFAOYSA-N uranium(0) Chemical compound [U] JFALSRSLKYAFGM-UHFFFAOYSA-N 0.000 description 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
- G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
- G01J3/02—Details
-
- 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
- G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
- G01J3/02—Details
- G01J3/0205—Optical elements not provided otherwise, e.g. optical manifolds, diffusers, windows
- G01J3/0213—Optical elements not provided otherwise, e.g. optical manifolds, diffusers, windows using attenuators
-
- 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
- G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
- G01J3/02—Details
- G01J3/0205—Optical elements not provided otherwise, e.g. optical manifolds, diffusers, windows
- G01J3/0218—Optical elements not provided otherwise, e.g. optical manifolds, diffusers, windows using optical fibers
-
- 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
- G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
- G01J3/28—Investigating the spectrum
- G01J3/42—Absorption spectrometry; Double beam spectrometry; Flicker spectrometry; Reflection spectrometry
Abstract
ABSTRACT OF THE DISCLOSURE
A spectrophotometric apparatus for measuring at a distance, of the type comprising a spectrophotometer having a light source, a detector, an optical system for defining a measuring light beam and a reference light beam and an optical well, further comprising:
- at least one measuring cell adapted to receive a solution to be analysed and at a distance from said spectro-photometer, - a measuring loop comprising a first optical system housed in said optical well for directing the measuring beam out of said optical well, a first fibre optic a first end of which receives said light beam whilst its other end is placed facing one or more lenses arranged on the input surface of the or each cell, at least one second fibre optic connecting one or more second lenses arranged on the output surface of the or each cell at an input of said optical well, and a second optical system housed in said optical well and adapted to direct the light beam emitted by said second fibre optic out of said well towards said emitter, and - a reference loop comprising a third optical system housed in said optical well for directing the reference beam out of said optical well, at least one fibre optic a first end of which receives said measuring light beam, whilst the other end is connected to an input of said optical well and a fourth optical system adapted to direct the light beam emitted by said fibre optic towards said detector, said fibre optic of the reference loop being of a length and a nature such that the reference loop substantially compensates the measuring loop.
A spectrophotometric apparatus for measuring at a distance, of the type comprising a spectrophotometer having a light source, a detector, an optical system for defining a measuring light beam and a reference light beam and an optical well, further comprising:
- at least one measuring cell adapted to receive a solution to be analysed and at a distance from said spectro-photometer, - a measuring loop comprising a first optical system housed in said optical well for directing the measuring beam out of said optical well, a first fibre optic a first end of which receives said light beam whilst its other end is placed facing one or more lenses arranged on the input surface of the or each cell, at least one second fibre optic connecting one or more second lenses arranged on the output surface of the or each cell at an input of said optical well, and a second optical system housed in said optical well and adapted to direct the light beam emitted by said second fibre optic out of said well towards said emitter, and - a reference loop comprising a third optical system housed in said optical well for directing the reference beam out of said optical well, at least one fibre optic a first end of which receives said measuring light beam, whilst the other end is connected to an input of said optical well and a fourth optical system adapted to direct the light beam emitted by said fibre optic towards said detector, said fibre optic of the reference loop being of a length and a nature such that the reference loop substantially compensates the measuring loop.
Description
1136~8Z
SPECTROPHOTOI~ETRIC APPARATUS FOR ~EASURING AT A DISTANCE
__. _ _ BACKGROUND 0~ THE INVENTION
This invention relates to a spectrophotometric appa-ratus for measuring at a distance, More precisely, the invention relates to an apparatus with which it is possible, for example, to determine the content of a certain number of bodies in a solution by spectrophotometric analysis, the solution to be analysed being such that the sample to be analysed is not in the optical well of the spectrophotometer. This is the case, for example, when the solution to be analysed is radio-active and the cell containing this solution has to be placed inside a thick protective enclosure.
Obviously, an apparatus of this kind is in no way limited to determining the content of certain bodies in a solution, since, as is well known, spectrophotometry can also be used, by infra-red analysis, to determine a temper-ature, for example.
The use of colorimeters or photometers to measure the concentration in solution of various ion types by applying Beer's law is well known. In this context, the use of fibre optics for measuring the content of these various types in the solution at a distance is also well known. It is also well known to use fibre optics associ-ated with mirrors reflecting light in order to obtainmeasuring probes immersed in the solutions to be analysed within the scope of colorimeters. These probes may 113~;88Z
optionally have variable paths which are automatically recalibrated by computers. It is also known to use lenses at the outputs of bundles of flexible fibre optics for focusinO the light beam carried by the fibre o~tic or, on the other hand, for obtaining a parallel light beam.
However, when the types present in the solution which is to be analysed are ill-defined, it is preferable, if not essential, to make a spectral exploration of the sol-ution using an apparatus for scanning along the wavelengths by means of a prism or, better still, a holographic networ~.
lhe corresponding measuring apparatus is then called a spectrophotome-ter. However, when a ~pectrophotometer is used, the known arrangements provided when a colorimeter or a photometer is used no longer apply. In ~act, the sensitivity of spectrophotometers is significantly greater than t~at of conventional colorimeters and the known cir-cuits used with fibre optics for connecting the colorimeter to the cell in ~hich the solution is located are not applicable in the case of analysis usin~ a spectrophoto-meter.
The invention is applicable to various types of knownspectrophotometers. Of these spectrophotometers, one could mention the apparatus developed in the United States by Messrs BECKMAN (DK2, Acta IV, 52 . 40, 52 . 70, etc.), the apparatus made by Messrs PERKIN and EL~ER, the apparatus made by Messrs BAUSCH and LO~, those made by Messrs CARY, and, in France, those made by Messrs. JOBIN YVON or S.A.F.A.S.
SPECTROPHOTOI~ETRIC APPARATUS FOR ~EASURING AT A DISTANCE
__. _ _ BACKGROUND 0~ THE INVENTION
This invention relates to a spectrophotometric appa-ratus for measuring at a distance, More precisely, the invention relates to an apparatus with which it is possible, for example, to determine the content of a certain number of bodies in a solution by spectrophotometric analysis, the solution to be analysed being such that the sample to be analysed is not in the optical well of the spectrophotometer. This is the case, for example, when the solution to be analysed is radio-active and the cell containing this solution has to be placed inside a thick protective enclosure.
Obviously, an apparatus of this kind is in no way limited to determining the content of certain bodies in a solution, since, as is well known, spectrophotometry can also be used, by infra-red analysis, to determine a temper-ature, for example.
The use of colorimeters or photometers to measure the concentration in solution of various ion types by applying Beer's law is well known. In this context, the use of fibre optics for measuring the content of these various types in the solution at a distance is also well known. It is also well known to use fibre optics associ-ated with mirrors reflecting light in order to obtainmeasuring probes immersed in the solutions to be analysed within the scope of colorimeters. These probes may 113~;88Z
optionally have variable paths which are automatically recalibrated by computers. It is also known to use lenses at the outputs of bundles of flexible fibre optics for focusinO the light beam carried by the fibre o~tic or, on the other hand, for obtaining a parallel light beam.
However, when the types present in the solution which is to be analysed are ill-defined, it is preferable, if not essential, to make a spectral exploration of the sol-ution using an apparatus for scanning along the wavelengths by means of a prism or, better still, a holographic networ~.
lhe corresponding measuring apparatus is then called a spectrophotome-ter. However, when a ~pectrophotometer is used, the known arrangements provided when a colorimeter or a photometer is used no longer apply. In ~act, the sensitivity of spectrophotometers is significantly greater than t~at of conventional colorimeters and the known cir-cuits used with fibre optics for connecting the colorimeter to the cell in ~hich the solution is located are not applicable in the case of analysis usin~ a spectrophoto-meter.
The invention is applicable to various types of knownspectrophotometers. Of these spectrophotometers, one could mention the apparatus developed in the United States by Messrs BECKMAN (DK2, Acta IV, 52 . 40, 52 . 70, etc.), the apparatus made by Messrs PERKIN and EL~ER, the apparatus made by Messrs BAUSCH and LO~, those made by Messrs CARY, and, in France, those made by Messrs. JOBIN YVON or S.A.F.A.S.
-2-.
113~ 2 It should be pointed out, in particular, thatwithin the framework of the use of spectrophotometers, the monochromatic characteristics of the light beam to be transmitted, which are essential for this measure-ment, are not compatible with the known apparatus fortransmitting light information between the measuring cell and the photometer.
Moreover, it should be mentioned that, in known spectrophotometers, it is not possible to carry out measurements at a distance. More precisely, the spectrophotometer has an optical well located directly opposite the spectrophotometers in which the reference and measuring cells are placed, the latter cell con-taining the solution which is to be analyzed. It will readily be understood that, if the solution to be analyzed is radioactive, for example, the measuring cell has to be protected and it is impossible to place it in the optical well. Now, as has been pointed out herein-before, the transmission of light information between the spectrophotometer and the cell presents particular problems which can be resolved with the invention.
It should also be pointed out that the Appli-cant has already developed a number of types of photo-metric cells with multiple reflexions which make it possible, for a cell of limited geometric dimensions, to provide an optical path of considerable length, for example of the order of one metre long, for the light beam passing through the solution. For further details of this type of cell, reference may advantageously be made to French patent 2,3~0,725 published on December
113~ 2 It should be pointed out, in particular, thatwithin the framework of the use of spectrophotometers, the monochromatic characteristics of the light beam to be transmitted, which are essential for this measure-ment, are not compatible with the known apparatus fortransmitting light information between the measuring cell and the photometer.
Moreover, it should be mentioned that, in known spectrophotometers, it is not possible to carry out measurements at a distance. More precisely, the spectrophotometer has an optical well located directly opposite the spectrophotometers in which the reference and measuring cells are placed, the latter cell con-taining the solution which is to be analyzed. It will readily be understood that, if the solution to be analyzed is radioactive, for example, the measuring cell has to be protected and it is impossible to place it in the optical well. Now, as has been pointed out herein-before, the transmission of light information between the spectrophotometer and the cell presents particular problems which can be resolved with the invention.
It should also be pointed out that the Appli-cant has already developed a number of types of photo-metric cells with multiple reflexions which make it possible, for a cell of limited geometric dimensions, to provide an optical path of considerable length, for example of the order of one metre long, for the light beam passing through the solution. For further details of this type of cell, reference may advantageously be made to French patent 2,3~0,725 published on December
- 3 -8, 1978 in the name of the Applicant, for "Photometric apparatus with concave mirrors and field optics" and to French patent 2,421,376 published in the Applicant's name on October 26, 1979 for "Photometric cell with multiple reflexions". It need only be mentioned that, thanks to these cells having special features enabling the optical path in the cell to be lengthened, it is possible to analyze solutions having only traces of the body to be detected. In fact, Beer's law, which concerns the relationship between the concentration of a body in a solution and the light absorption resulting from the presence of this body, means that the ab-sorption is proportional to the length of the optical path travelled by the light beam. Thus, by increasing this light path by means of a suitable optical system, the sensitivity of the apparatus is increased or, in the same way, the sensitivity of the apparatus is kept the same, even for solutions with very low concen-trations.
BRIEF SUMMARY OF THE INVENTION
This invention relates precisely to an apparatus for spectrophotometric measurement, at a distance, of species in solution, which comprises specific means ensuring the transmission of the light signal between the analysis cell containing the solution to be analyzed and the spectrophotometer, with which very precise analysis can be carried out.
Moreover, without affecting the precision of the measurement, the apparatus makes it possible to have a ,X
substantial distance between the position of the cell con-taining the solution to be analysed and the spectrophotometer.
In particular (although this is not restrictive), this apparatus makes it possible to have a substanti~l distance of this kind between the spectrophotometer and the cell, when the latteE is placed in a radiation-prooI enclosure, i.e. when the solution to be analysed is radioactive.
Moreover, within the scope of the transmission of optical information by fibre optics and in the case of a measuring cell containing a radioactive solution placed in a protect-ive enclosure, the special features of the apparatus allow it to be freed from the effects of radiation, particularly gamma radiation, on the variations in absorption of the - fibre optic in the transmission of light. In particular, now that the inventors have shown that this variation in absorption also depends on the wavelengths of the ligh~
beam, the invention permits a correction as a function of the wavelength used for the spectrophotometry.
The apparatus according to the invention comprises a spectrophotometer having a light source, a detector, an optical system for defining a measuring light beam and a reference light beam and an optical well and is character-ised in that it also comprises:
- at least one measuring cell adapted to receive a solution to be analysed and at a distance from said spectrophotometer, - a measuring loop comprising a first optical system ` 113~;~82 housed in said optical well for directing the measuring beam out of said optical well, a first fibre optic a first end of which receives said light beam whilst its other end is placed ~acing one or more lenses arranged on the input surface of the or each cell, at least one second fibre optic connecting one or more second lenses arranged on the output surface of the or each cell to an input of said optical well, and a second optical system housed in said optical well and adapted to direct the light beam emitted by said said fibre optic out of said well towards said detector, and - a reference loop comprising a third optical system housed in said optical well for directing the reference beam out of said optical well, at least one ~ibre optic, a first end of which receives said measuring light beam whilst its other end is connected to an input of said optical well and a fourth optical system adapted to direct the light beam emit+ed by said fibre optic towards said detector, said fibre optic of the reference loop being of a length and nature such that the reference loop substantially compensates the measuring loop.
According to a preferred embodiment, the reference loop co~prises a reference cell adapted to receive a refer-ence solution and the fibre optic of the reference loop is made up of two portions of fibre optic between which is placed the reference cell, via two lenses.
According to a preferred embodiment, the or each measuring cell is housed in a protective enclosure, each of ! 6 ~13~ Z
the two fibre optics of the measuring loop is made up of two half-fibre optics between which is placed a system for passing through said protective wall.
BRIEF DESCRI~TION OF THE D~AIINGS
In any case, the invention will be more readily understood from the following description of an embodiment of the invention given by way of a non-restrictive example.
The description refers to the accompanying drawings, wherein:
Figure 1 is a view of the entire apparatus for ~pectro-photometric analysis at a distance, Figure 2 is a simplified view of the optical system of the apparatus according to the invention and the form of the light beam in the different parts o~ the apparatus, Figures 3 and 4 show curves representing the optical density as a function of the wavelength, for an apparatus not compensated by fibre optics and for the apparatus acc-ording to the invention, respectively, and Figure 5 shows curves representing the optical density as a function of the ~lavelength by using a cell of consid-erable optical travel distance in an apparatus partially compensated by a fibre optic.
DETAILED DES~RIPTION OF THE PR~FERRED EI~BODI~ENTS
First of all, the apparatus accordirg to the invention comprises a conventional spectrophotometer, i.e. one having a monochromatic source 1 controlled by a wavelength scanning device 2. Associated with this monochromatic source is a ` 113~;~82 slot of adjustable width 1' by means of which the light energy emitted can be controlled. This spectrophotometer also contains a system of two pivoting mirrors 22 and 22' controlle~ by the mechanism 3 which is snown in simplified symbolical form in Figure 1. Between these two mirrors 22 and 22' the optical well 4 of the spectrophotometer is pro-vided in known manner. Obviously, the planar mirrors 23 and 23' are also located outside the optical well. As indicated above, all the components described correspond to a spectro-photometer of the conventional type.
In one important embodiment of the invention, thetank 14 containing the solution to be analysed is placèd inside an armoured protective enclosure 10 and there may be a substantial distance between the cell 14 and the spectro-photometer proper. Generally, it can be said that thespectrophotometer is equipped with a measuring loop having the reference I, which connects the spectrophotometer to the measuring cell 14 and, preferably, a reference loop II
which connects the spectrophotometer proper to the refer-2~ ence or control cell 32. The measuring loop I and thereference loop II will be described hereinafter.
A planzr or preferably spherical or parabolic mirror 5 is placed in the optical well 4 for sending the measuring light beam outwards. A convergent focusi~g lens for the light beam ensures that this beam is focused towards the input surface 7 of a first fibre optic 8~ The wall 10 of the protective enclosure is preferably penetrated by fibre 113G~8Z
optics 11 of the "selfoc" type. In other words, the fibre optics are of a special kind which produce a divergence or convergence of the light beam at their outputs. They therefore behave like a normal fibre optic associated with two lenses. Of course, the special type of fibre optic 11 could be replaced by a port associated with the two lenses. However, fibre optics such as those known under the trademark SELFOC
have numerous advantages for the mounting of the means passing through the enclosure 10 and, in particular, for the problems of making these means pass through in leak-tight manner. The fibre optic 8 is extended inside the enclosure 10 by a fibre 12 associated with a lens 13 which makes the light beam parallel at the entry to the measuring cell 14. At the exit from the cell 14 there is a convergent lens 15 which sends the light beam leav-ing the cell towards the input surface of a fibre optic 16 connected to penetrating means 11' identical to the penetrating means 11. As has already been mentioned, the cell 14 is filled with the solution to be analyzed.
The apparatus is more particularly applicable to cases where this solution has very great radioactivity, hence the need to place this cell inside the enclosure 10.
The measuring light beam is returned by means of the fibre optic 17 from the lens 19 placed inside the well 4 which gives a parallel light beam from the divergent beam emitted by the output surface 18 of the fibre optic 17. There is then a planar mirror 20 for returning the light beam from the well 4 towards the detector 21.
113~;~8Z
Moreover, an adjustable photometric -~edge 9 constituting an equilibrating system may be interposed in the circuit con-sisting of the fibre optic 8. It should be added that the enclosure 10 may contain a plurality of measuring cells.
In fact, multi-strand fibre optics may be used. Each strand may be separated in the protective enclosure and correspond to a measuring cell. Moreover, the fibre optics used are made of a material which withstands the doses of irradiation present. Silica fibres may be used, for example. If the measuring cell is not placed in a protective enclosure, there are no problems as regards penetrating the wall and the fibres ~ and 12 and 16 and 17 form only one fibre, respect-ively.
As the reference loop II has substantially the same structure as the measuring loop I in the fullset embodiment, - it will be described in less detail, with only its differ-ences emphasised.This loop comprises a planar or preferably spherical or parabolic mirror 24, the convergent lens 25 which enables the reference light beam to leave the optical well 4, the fibre optic 27 with its input end 26, the other end of the fibre 27 being associated with a lens 31 provid-ing at its output a parallel light beam at the entry to the reference cell 32. At the output from the latter there is a convergent lens 33 and a second fibre optic 34 the output surface 35 of which causes the light bea~ to penetrate into the optical well 4. Inside the latter is the lens 36 which returns a parallel light beam to the planar mirror 37, 113~i8~Z
whilst the latter sends the reference light beam to themirror 23'. Also provided in this circuit is a compensating photometric wedge 28 having the same function as the wedge 9 in measuring loop I and a second adjusting photometric wedge 40.
As has already been pointed out, according to a preferred feature of the invention, this apparatus is used when the measuring cell 14 contains highly radioactive solutions. Now, the inventors have found that when fibre optics were subjected to radiation, for example intense gamma radiation, there was a modification of the character-istics of the fibre optic and more particularly a modifi-cation of the coefficient of absorption of this fibre as a ~ function of the dose received. They also found that this 15 variation in the coefficient of absorption was also a func- -tion of the wavelength of the light beam passing through the fibre optic. This is why the regulating photometric wedge 40 is associated with a control which is a function of the wavelength. For this purpose, the movements of the wedge 40 are controlled via a means 29 which is itself con-trolled by a microprocessor 30 controlled by a signal taken from the scanning circuit 2. Thus, the position of the wedge 40 is controlled as a function of the wavelength used in the circuit at the moment in ~uestion. It should be added that micrometric mechanisms 38 and 39 can be used to regulate the position of the mirrors 5, 20, 24 and 37 and the ends 7, 18, 26 and 35 of the fibre optics exactly.
~13~;~82 It will be ap~reciated, in fact, that in view of the very small diameter of the fibre optics it is essential -that all the light beams actually strike the input surfaces of the fibres in order to obLain the optimum yield.
Referring to Figure 2, this shows the propagation of the light beam in the measuring loop I. This enables one to appreciate the action of the different optical means.
Obviously, the reference numerals previously used in Fig.
1 have also been used in this figure.
Compared with the complete assembly shown in Figure 1, the following comments can be made regarding alter-naiive embodiments. It would be possible for part of the reference loop to be located in an irradiating medium, i.e.
inside the cell of the enclosure 10, for example. There would then be a certain compensation between the measuring path and the reference path as to the effects of the irrad-iation.
In certain cases, the apparatus can be used as a single beam apparatus, i.e. having only the measuring path.
The measuring or reference apparatus can thus be determined spectrally.
It would also be possible for the reference path II
to consist only of a single fibre optic outside the optical well. The single fibre oDtic thus used is selected so as to give the same attenuation as the complete measuring circuit. For this, a fibre optic of suitable length and made from a suitable material is chosen.
113~82 Moreover, the measuring or reference cells may be either of conventional design or of a special design, like those described in the two patents referred to above.
More appropriately, the apparatus can be used for measuring non-radioactive elements which therefore have no protective enclosure, e.g. for measuring traces with tanks having a long optical path, connected by fibre optics, the results of which are shown in Figure 5.
Moreover, it is important to point out that the spectrophotometer per se is conventional and that, as regards this part, the only difference is that instead of placing the measuring and reference cells in the opti-cal well, the optical return systems are placed therein.
The effectiveness of the measuring apparatus according to the invention and, in particular, the compensation effect will be more readily appreciated from the curves in Figures 3 and 4.
In Figure 3, which gives the optical density (in arbitrary units) as a function of the wavelength (in nm) for a neodyme solution (10.0458 g of neodyme nitrate in 100 cc of 10~ HNO3) in an apparatus without compensation, the curve I gives the base line corre-sponding to a solution containing only 10~ HNO3, whilst curve II gives the spectral analysis of the solution.
It will be noted that the base line is by no means horizontal and that it is very difficult to interpret curve II directly.
1 1 3~ ~ ~Z
Figure 4 shows the curves corresponding to the same analysis, but with the compensation obtained with the reference loop. Curve I corresponds to pure HN03, and curves II, III, IV and V correspond to nitrate concentra-tions of 1/4, 1/2, 3/4 and 1, respectively.
- --- It will be seen that the base line I is substantially horizontal over a wide range of wavelengths from 470 nm to 850 nm. The characteristic measuring peaks also appear very distinctly. This figure also shows the variations in optical density (DØ) as a function of the concentration (C/4, C/2, 3C/4, C) for the peaks 524, 575 and 741. This curve shows that Beer's law is indeed verified with the apparatus according to the invention.
Figure 5 shows the curves which give the optical density (DØ) as a function of the wavelength (A) for a solution of 0.05 g of neodyme per 100 cc of 10~ HN03 in an apparatus partially compensated by a fibre optic and using a tank with a long optical travel distance connected by fibres. The curve I corresponds to pure HN03, whilst curves II, III, IV and V correspond to nitrate concent~at-ions of 1/4, 1/2 ~ 1 and 3/2 9 respectively. It will be seen that the base line is substantially horizontal between 470 nm and 580 nm. The characteristic peaks appear clearly on the added curve which gives the optical density (DØ) as a function of the concentration C.
It is also possible to work in white light. A filter is placed behind the measuring cell. In this way, the ;8~ilZ
response in the spectral band defined by the filter can be studied .
The foregoing description shows that the apparatusaccordin~T to the invention nakes it possible to mal~e spec-tral measurements of solutions with a high degree of pre-cision, even though the measurements are made at a distance and in an enclosure in an active medium.
The fixed compensation system (using fibre optics~
is easy to use. Microprocessor control permits better linearisation of the base line and compensation of the drift caused by the attenuation of the transmission of the fibre optics under the effect of radiation.
As an alternative, it should be pointed out that the mirrors 5? 20, 24 and 37 couid be replaced by portions of fibre optics bent at right angles, enabling the light be m to be returned at 90. Obviously, these portions of fibre optics should be associated with suitable lensesD
This apparatus can be used, in particular, for valency measurements of uranium, plutonium and neptunium in near infra-red and~ with tanks having a long optical travel path, for analysing traces of these substances in solution. Thanks to its compensation system, it can be used in wavelength ranges from ultra-violet to infra-red.
It should also be emphasised that the n~easuring loop is fully reversible, In other words, without modifying the loop, the monochromator 1 and detector 21 can be inter-changed. This reversibility means that in certain apparatus ;882 it is possible to work in the infra-red mode; i.e, with a source of white light, whilst the monochromy is then ob-tained downstream of the apparatus described.
The invention is not limited to the embodiments described and represented hereinbefore and various modif-ications can be made thereto without passing beyond the scope of the invention.
BRIEF SUMMARY OF THE INVENTION
This invention relates precisely to an apparatus for spectrophotometric measurement, at a distance, of species in solution, which comprises specific means ensuring the transmission of the light signal between the analysis cell containing the solution to be analyzed and the spectrophotometer, with which very precise analysis can be carried out.
Moreover, without affecting the precision of the measurement, the apparatus makes it possible to have a ,X
substantial distance between the position of the cell con-taining the solution to be analysed and the spectrophotometer.
In particular (although this is not restrictive), this apparatus makes it possible to have a substanti~l distance of this kind between the spectrophotometer and the cell, when the latteE is placed in a radiation-prooI enclosure, i.e. when the solution to be analysed is radioactive.
Moreover, within the scope of the transmission of optical information by fibre optics and in the case of a measuring cell containing a radioactive solution placed in a protect-ive enclosure, the special features of the apparatus allow it to be freed from the effects of radiation, particularly gamma radiation, on the variations in absorption of the - fibre optic in the transmission of light. In particular, now that the inventors have shown that this variation in absorption also depends on the wavelengths of the ligh~
beam, the invention permits a correction as a function of the wavelength used for the spectrophotometry.
The apparatus according to the invention comprises a spectrophotometer having a light source, a detector, an optical system for defining a measuring light beam and a reference light beam and an optical well and is character-ised in that it also comprises:
- at least one measuring cell adapted to receive a solution to be analysed and at a distance from said spectrophotometer, - a measuring loop comprising a first optical system ` 113~;~82 housed in said optical well for directing the measuring beam out of said optical well, a first fibre optic a first end of which receives said light beam whilst its other end is placed ~acing one or more lenses arranged on the input surface of the or each cell, at least one second fibre optic connecting one or more second lenses arranged on the output surface of the or each cell to an input of said optical well, and a second optical system housed in said optical well and adapted to direct the light beam emitted by said said fibre optic out of said well towards said detector, and - a reference loop comprising a third optical system housed in said optical well for directing the reference beam out of said optical well, at least one ~ibre optic, a first end of which receives said measuring light beam whilst its other end is connected to an input of said optical well and a fourth optical system adapted to direct the light beam emit+ed by said fibre optic towards said detector, said fibre optic of the reference loop being of a length and nature such that the reference loop substantially compensates the measuring loop.
According to a preferred embodiment, the reference loop co~prises a reference cell adapted to receive a refer-ence solution and the fibre optic of the reference loop is made up of two portions of fibre optic between which is placed the reference cell, via two lenses.
According to a preferred embodiment, the or each measuring cell is housed in a protective enclosure, each of ! 6 ~13~ Z
the two fibre optics of the measuring loop is made up of two half-fibre optics between which is placed a system for passing through said protective wall.
BRIEF DESCRI~TION OF THE D~AIINGS
In any case, the invention will be more readily understood from the following description of an embodiment of the invention given by way of a non-restrictive example.
The description refers to the accompanying drawings, wherein:
Figure 1 is a view of the entire apparatus for ~pectro-photometric analysis at a distance, Figure 2 is a simplified view of the optical system of the apparatus according to the invention and the form of the light beam in the different parts o~ the apparatus, Figures 3 and 4 show curves representing the optical density as a function of the wavelength, for an apparatus not compensated by fibre optics and for the apparatus acc-ording to the invention, respectively, and Figure 5 shows curves representing the optical density as a function of the ~lavelength by using a cell of consid-erable optical travel distance in an apparatus partially compensated by a fibre optic.
DETAILED DES~RIPTION OF THE PR~FERRED EI~BODI~ENTS
First of all, the apparatus accordirg to the invention comprises a conventional spectrophotometer, i.e. one having a monochromatic source 1 controlled by a wavelength scanning device 2. Associated with this monochromatic source is a ` 113~;~82 slot of adjustable width 1' by means of which the light energy emitted can be controlled. This spectrophotometer also contains a system of two pivoting mirrors 22 and 22' controlle~ by the mechanism 3 which is snown in simplified symbolical form in Figure 1. Between these two mirrors 22 and 22' the optical well 4 of the spectrophotometer is pro-vided in known manner. Obviously, the planar mirrors 23 and 23' are also located outside the optical well. As indicated above, all the components described correspond to a spectro-photometer of the conventional type.
In one important embodiment of the invention, thetank 14 containing the solution to be analysed is placèd inside an armoured protective enclosure 10 and there may be a substantial distance between the cell 14 and the spectro-photometer proper. Generally, it can be said that thespectrophotometer is equipped with a measuring loop having the reference I, which connects the spectrophotometer to the measuring cell 14 and, preferably, a reference loop II
which connects the spectrophotometer proper to the refer-2~ ence or control cell 32. The measuring loop I and thereference loop II will be described hereinafter.
A planzr or preferably spherical or parabolic mirror 5 is placed in the optical well 4 for sending the measuring light beam outwards. A convergent focusi~g lens for the light beam ensures that this beam is focused towards the input surface 7 of a first fibre optic 8~ The wall 10 of the protective enclosure is preferably penetrated by fibre 113G~8Z
optics 11 of the "selfoc" type. In other words, the fibre optics are of a special kind which produce a divergence or convergence of the light beam at their outputs. They therefore behave like a normal fibre optic associated with two lenses. Of course, the special type of fibre optic 11 could be replaced by a port associated with the two lenses. However, fibre optics such as those known under the trademark SELFOC
have numerous advantages for the mounting of the means passing through the enclosure 10 and, in particular, for the problems of making these means pass through in leak-tight manner. The fibre optic 8 is extended inside the enclosure 10 by a fibre 12 associated with a lens 13 which makes the light beam parallel at the entry to the measuring cell 14. At the exit from the cell 14 there is a convergent lens 15 which sends the light beam leav-ing the cell towards the input surface of a fibre optic 16 connected to penetrating means 11' identical to the penetrating means 11. As has already been mentioned, the cell 14 is filled with the solution to be analyzed.
The apparatus is more particularly applicable to cases where this solution has very great radioactivity, hence the need to place this cell inside the enclosure 10.
The measuring light beam is returned by means of the fibre optic 17 from the lens 19 placed inside the well 4 which gives a parallel light beam from the divergent beam emitted by the output surface 18 of the fibre optic 17. There is then a planar mirror 20 for returning the light beam from the well 4 towards the detector 21.
113~;~8Z
Moreover, an adjustable photometric -~edge 9 constituting an equilibrating system may be interposed in the circuit con-sisting of the fibre optic 8. It should be added that the enclosure 10 may contain a plurality of measuring cells.
In fact, multi-strand fibre optics may be used. Each strand may be separated in the protective enclosure and correspond to a measuring cell. Moreover, the fibre optics used are made of a material which withstands the doses of irradiation present. Silica fibres may be used, for example. If the measuring cell is not placed in a protective enclosure, there are no problems as regards penetrating the wall and the fibres ~ and 12 and 16 and 17 form only one fibre, respect-ively.
As the reference loop II has substantially the same structure as the measuring loop I in the fullset embodiment, - it will be described in less detail, with only its differ-ences emphasised.This loop comprises a planar or preferably spherical or parabolic mirror 24, the convergent lens 25 which enables the reference light beam to leave the optical well 4, the fibre optic 27 with its input end 26, the other end of the fibre 27 being associated with a lens 31 provid-ing at its output a parallel light beam at the entry to the reference cell 32. At the output from the latter there is a convergent lens 33 and a second fibre optic 34 the output surface 35 of which causes the light bea~ to penetrate into the optical well 4. Inside the latter is the lens 36 which returns a parallel light beam to the planar mirror 37, 113~i8~Z
whilst the latter sends the reference light beam to themirror 23'. Also provided in this circuit is a compensating photometric wedge 28 having the same function as the wedge 9 in measuring loop I and a second adjusting photometric wedge 40.
As has already been pointed out, according to a preferred feature of the invention, this apparatus is used when the measuring cell 14 contains highly radioactive solutions. Now, the inventors have found that when fibre optics were subjected to radiation, for example intense gamma radiation, there was a modification of the character-istics of the fibre optic and more particularly a modifi-cation of the coefficient of absorption of this fibre as a ~ function of the dose received. They also found that this 15 variation in the coefficient of absorption was also a func- -tion of the wavelength of the light beam passing through the fibre optic. This is why the regulating photometric wedge 40 is associated with a control which is a function of the wavelength. For this purpose, the movements of the wedge 40 are controlled via a means 29 which is itself con-trolled by a microprocessor 30 controlled by a signal taken from the scanning circuit 2. Thus, the position of the wedge 40 is controlled as a function of the wavelength used in the circuit at the moment in ~uestion. It should be added that micrometric mechanisms 38 and 39 can be used to regulate the position of the mirrors 5, 20, 24 and 37 and the ends 7, 18, 26 and 35 of the fibre optics exactly.
~13~;~82 It will be ap~reciated, in fact, that in view of the very small diameter of the fibre optics it is essential -that all the light beams actually strike the input surfaces of the fibres in order to obLain the optimum yield.
Referring to Figure 2, this shows the propagation of the light beam in the measuring loop I. This enables one to appreciate the action of the different optical means.
Obviously, the reference numerals previously used in Fig.
1 have also been used in this figure.
Compared with the complete assembly shown in Figure 1, the following comments can be made regarding alter-naiive embodiments. It would be possible for part of the reference loop to be located in an irradiating medium, i.e.
inside the cell of the enclosure 10, for example. There would then be a certain compensation between the measuring path and the reference path as to the effects of the irrad-iation.
In certain cases, the apparatus can be used as a single beam apparatus, i.e. having only the measuring path.
The measuring or reference apparatus can thus be determined spectrally.
It would also be possible for the reference path II
to consist only of a single fibre optic outside the optical well. The single fibre oDtic thus used is selected so as to give the same attenuation as the complete measuring circuit. For this, a fibre optic of suitable length and made from a suitable material is chosen.
113~82 Moreover, the measuring or reference cells may be either of conventional design or of a special design, like those described in the two patents referred to above.
More appropriately, the apparatus can be used for measuring non-radioactive elements which therefore have no protective enclosure, e.g. for measuring traces with tanks having a long optical path, connected by fibre optics, the results of which are shown in Figure 5.
Moreover, it is important to point out that the spectrophotometer per se is conventional and that, as regards this part, the only difference is that instead of placing the measuring and reference cells in the opti-cal well, the optical return systems are placed therein.
The effectiveness of the measuring apparatus according to the invention and, in particular, the compensation effect will be more readily appreciated from the curves in Figures 3 and 4.
In Figure 3, which gives the optical density (in arbitrary units) as a function of the wavelength (in nm) for a neodyme solution (10.0458 g of neodyme nitrate in 100 cc of 10~ HNO3) in an apparatus without compensation, the curve I gives the base line corre-sponding to a solution containing only 10~ HNO3, whilst curve II gives the spectral analysis of the solution.
It will be noted that the base line is by no means horizontal and that it is very difficult to interpret curve II directly.
1 1 3~ ~ ~Z
Figure 4 shows the curves corresponding to the same analysis, but with the compensation obtained with the reference loop. Curve I corresponds to pure HN03, and curves II, III, IV and V correspond to nitrate concentra-tions of 1/4, 1/2, 3/4 and 1, respectively.
- --- It will be seen that the base line I is substantially horizontal over a wide range of wavelengths from 470 nm to 850 nm. The characteristic measuring peaks also appear very distinctly. This figure also shows the variations in optical density (DØ) as a function of the concentration (C/4, C/2, 3C/4, C) for the peaks 524, 575 and 741. This curve shows that Beer's law is indeed verified with the apparatus according to the invention.
Figure 5 shows the curves which give the optical density (DØ) as a function of the wavelength (A) for a solution of 0.05 g of neodyme per 100 cc of 10~ HN03 in an apparatus partially compensated by a fibre optic and using a tank with a long optical travel distance connected by fibres. The curve I corresponds to pure HN03, whilst curves II, III, IV and V correspond to nitrate concent~at-ions of 1/4, 1/2 ~ 1 and 3/2 9 respectively. It will be seen that the base line is substantially horizontal between 470 nm and 580 nm. The characteristic peaks appear clearly on the added curve which gives the optical density (DØ) as a function of the concentration C.
It is also possible to work in white light. A filter is placed behind the measuring cell. In this way, the ;8~ilZ
response in the spectral band defined by the filter can be studied .
The foregoing description shows that the apparatusaccordin~T to the invention nakes it possible to mal~e spec-tral measurements of solutions with a high degree of pre-cision, even though the measurements are made at a distance and in an enclosure in an active medium.
The fixed compensation system (using fibre optics~
is easy to use. Microprocessor control permits better linearisation of the base line and compensation of the drift caused by the attenuation of the transmission of the fibre optics under the effect of radiation.
As an alternative, it should be pointed out that the mirrors 5? 20, 24 and 37 couid be replaced by portions of fibre optics bent at right angles, enabling the light be m to be returned at 90. Obviously, these portions of fibre optics should be associated with suitable lensesD
This apparatus can be used, in particular, for valency measurements of uranium, plutonium and neptunium in near infra-red and~ with tanks having a long optical travel path, for analysing traces of these substances in solution. Thanks to its compensation system, it can be used in wavelength ranges from ultra-violet to infra-red.
It should also be emphasised that the n~easuring loop is fully reversible, In other words, without modifying the loop, the monochromator 1 and detector 21 can be inter-changed. This reversibility means that in certain apparatus ;882 it is possible to work in the infra-red mode; i.e, with a source of white light, whilst the monochromy is then ob-tained downstream of the apparatus described.
The invention is not limited to the embodiments described and represented hereinbefore and various modif-ications can be made thereto without passing beyond the scope of the invention.
Claims (6)
1. Spectrophotometric apparatus for measuring at a distance, of the type comprising a spectrophoto-meter having a light source, a detector, an optical system for defining a measuring light beam and a refer-ence light beam and an optical well, wherein this appa-ratus further comprises:
- at least one measuring cell adapted to receive a solution to be analyzed and at a distance from said spectrophotometer, - a measuring loop comprising a first optical system housed in said optical well for directing the measuring beam out of said optical well, a first fibre optic a first end of which receives said measuring light beam whilst its other end is placed facing one or more lenses arranged on the input surface of the or each cell, at least one second fibre optic connecting one or more second lenses arranged on the output surface of the or each cell at an input of said optical well, and a second optical system housed in said optical well and adapted to direct the light beam emitted by said second fibre optic out of said well towards said detector, and - a reference loop comprising a third optical system housed in said optical well for directing the reference beam out of said optical well, at least one fibre optic a first end of which receives said reference light beam, whilst the other end is connected to an input of said optical well and a fourth optical system adapted to direct the light beam emitted by said fibre optic towards said detector, said fibre optic of the reference loop being of a length and a nature such that the reference loop substantially compensates possible modifications in the characteristics of the fiber optics of the measuring loop overtime.
- at least one measuring cell adapted to receive a solution to be analyzed and at a distance from said spectrophotometer, - a measuring loop comprising a first optical system housed in said optical well for directing the measuring beam out of said optical well, a first fibre optic a first end of which receives said measuring light beam whilst its other end is placed facing one or more lenses arranged on the input surface of the or each cell, at least one second fibre optic connecting one or more second lenses arranged on the output surface of the or each cell at an input of said optical well, and a second optical system housed in said optical well and adapted to direct the light beam emitted by said second fibre optic out of said well towards said detector, and - a reference loop comprising a third optical system housed in said optical well for directing the reference beam out of said optical well, at least one fibre optic a first end of which receives said reference light beam, whilst the other end is connected to an input of said optical well and a fourth optical system adapted to direct the light beam emitted by said fibre optic towards said detector, said fibre optic of the reference loop being of a length and a nature such that the reference loop substantially compensates possible modifications in the characteristics of the fiber optics of the measuring loop overtime.
2. Apparatus according to Claim 1, wherein the or each measuring cell is housed in a protective enclosure and each of the two fibre optics of the measuring loop is made up of two half-fibre optics between which is interposed a system for penetrating said protective wall.
3. Apparatus according to Claim 1, wherein the reference loop comprises a reference cell adapted to receive a reference solution and wherein said fibre optic of the reference loop is made up of two portions of fibre optic between which is placed said reference cell by means of two lens.
4. Apparatus according to Claim 2, wherein the measuring solution is radioactive and part of the fibre optic of the reference loop is housed in said enclosure.
5. Apparatus according to Claim 2, wherein the measuring solution is radioactive and the fibre optic of the reference loop comprises an adjusting photometric wedge whose position is controlled in value and synchronized with the wavelength control of the light source, in such a way that the wedge compensates for the effect of radiation on the fibre optics of the measuring loop housed in said enclosure.
6. Apparatus according to Claim 1, wherein compensating photometric wedges for equilibrating the two light beams are interposed in the measuring and/or reference loops.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FREN7902297 | 1979-01-30 | ||
| FR7902297A FR2448134A1 (en) | 1979-01-30 | 1979-01-30 | SPECTROPHOTOMETRIC DEVICE FOR REMOTE MEASUREMENT |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1136882A true CA1136882A (en) | 1982-12-07 |
Family
ID=9221346
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000344463A Expired CA1136882A (en) | 1979-01-30 | 1980-01-28 | Spectrophotometric apparatus for remote measuring |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0015170B1 (en) |
| JP (1) | JPS55132923A (en) |
| CA (1) | CA1136882A (en) |
| DE (1) | DE3063792D1 (en) |
| ES (1) | ES8103837A1 (en) |
| FR (1) | FR2448134A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4632563A (en) * | 1983-02-28 | 1986-12-30 | The Syconex Corporation | In-situ gas analyzer |
| US9810558B2 (en) | 2014-03-14 | 2017-11-07 | Particle Measuring Systems, Inc. | Pressure-based airflow sensing in particle impactor systems |
Families Citing this family (20)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4529308A (en) * | 1982-05-28 | 1985-07-16 | Hunter Associates Laboratory, Inc. | Spectrophotometer apparatus and method including scale drift correction feature |
| GB2159940A (en) * | 1984-06-01 | 1985-12-11 | Stc Plc | Remote optical sensors |
| DE3430050A1 (en) * | 1984-08-16 | 1986-04-10 | Betz, Michael, Dr., 2300 Molfsee | Photometer for the analysis of aqueous media |
| FR2569864B1 (en) * | 1984-09-04 | 1987-01-30 | Commissariat Energie Atomique | OPTICAL FIBER LIGHT EMITTING AND DISTRIBUTION EQUIPMENT, PARTICULARLY FOR ONLINE SPECTROPHOTOMETER CONTROL USING A DOUBLE BEAM SPECTROPHOTOMETER |
| JPS6195220A (en) * | 1984-10-17 | 1986-05-14 | Hitachi Ltd | Spectrophotometer |
| JPS61108933A (en) * | 1984-11-01 | 1986-05-27 | Power Reactor & Nuclear Fuel Dev Corp | Remote control type spectrophotometer |
| JPS62124430A (en) * | 1985-11-25 | 1987-06-05 | Sanyo Kokusaku Pulp Co Ltd | Device and method for measuring color density |
| SE8802536D0 (en) * | 1988-07-07 | 1988-07-07 | Altoptronic Ab | METHOD AND APPARATUS FOR SPECTROSCOPIC MEASUREMENT OF THE CONCENTRATION OF A GAS IN A SAMPLE |
| US5039855A (en) * | 1990-03-05 | 1991-08-13 | Bran+Luebbe Analyzing Technologies, Inc. | Dual beam acousto-optic tunable spectrometer |
| US5742399A (en) * | 1996-04-18 | 1998-04-21 | American Air Liquide, Inc. | Method for stabilizing the wavelength in a laser spectrometer system |
| US5818578A (en) * | 1995-10-10 | 1998-10-06 | American Air Liquide Inc. | Polygonal planar multipass cell, system and apparatus including same, and method of use |
| US5963336A (en) * | 1995-10-10 | 1999-10-05 | American Air Liquide Inc. | Chamber effluent monitoring system and semiconductor processing system comprising absorption spectroscopy measurement system, and methods of use |
| US5751422A (en) * | 1996-02-26 | 1998-05-12 | Particle Measuring Systems, Inc. | In-situ particle detection utilizing optical coupling |
| US5949537A (en) | 1996-04-18 | 1999-09-07 | American Air Liquide Inc. | In-line cell for absorption spectroscopy |
| US5880850A (en) * | 1996-04-18 | 1999-03-09 | American Air Liquide Inc | Method and system for sensitive detection of molecular species in a vacuum by harmonic detection spectroscopy |
| US5835230A (en) * | 1997-07-10 | 1998-11-10 | American Air Liquide Inc. | Method for calibration of a spectroscopic sensor |
| US6084668A (en) * | 1997-07-10 | 2000-07-04 | American Air Liquide Inc. | In-line cell for absorption spectroscopy |
| US6442736B1 (en) | 2000-10-03 | 2002-08-27 | L'air Liquide Societe Anonyme A Directoire Et Conseil De Surveillance Pour L'etude Et L'expolitation Des Procedes Georges Claude | Semiconductor processing system and method for controlling moisture level therein |
| JP2009002864A (en) * | 2007-06-22 | 2009-01-08 | Olympus Corp | Analysis apparatus and analysis method |
| WO2009073649A1 (en) | 2007-12-04 | 2009-06-11 | Particle Measuring Systems, Inc. | Non-orthogonal particle detection systems and methods |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1054767A (en) * | 1963-10-11 | 1900-01-01 | ||
| US3506459A (en) * | 1967-07-11 | 1970-04-14 | Pillsbury Co | Tamper-proof multiple compartment package |
| GB1290903A (en) * | 1969-11-18 | 1972-09-27 | ||
| US3805066A (en) * | 1972-08-14 | 1974-04-16 | T Chijuma | Smoke detecting device utilizing optical fibers |
| FR2317638A1 (en) * | 1975-07-09 | 1977-02-04 | Commissariat Energie Atomique | SYSTEM FOR ANALYSIS OF THE CONSTITUENTS OF A SOLUTION BY PHOTOMETRIC MEASUREMENT |
| JPS594258Y2 (en) * | 1976-12-11 | 1984-02-07 | オムロン株式会社 | double beam spectrophotometer |
-
1979
- 1979-01-30 FR FR7902297A patent/FR2448134A1/en active Granted
-
1980
- 1980-01-18 DE DE8080400081T patent/DE3063792D1/en not_active Expired
- 1980-01-18 EP EP19800400081 patent/EP0015170B1/en not_active Expired
- 1980-01-28 CA CA000344463A patent/CA1136882A/en not_active Expired
- 1980-01-29 JP JP923180A patent/JPS55132923A/en active Granted
- 1980-01-31 ES ES488067A patent/ES8103837A1/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4632563A (en) * | 1983-02-28 | 1986-12-30 | The Syconex Corporation | In-situ gas analyzer |
| US9810558B2 (en) | 2014-03-14 | 2017-11-07 | Particle Measuring Systems, Inc. | Pressure-based airflow sensing in particle impactor systems |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS55132923A (en) | 1980-10-16 |
| FR2448134A1 (en) | 1980-08-29 |
| FR2448134B1 (en) | 1982-02-05 |
| ES488067A0 (en) | 1981-02-16 |
| EP0015170B1 (en) | 1983-06-22 |
| EP0015170A1 (en) | 1980-09-03 |
| JPH0131130B2 (en) | 1989-06-23 |
| ES8103837A1 (en) | 1981-02-16 |
| DE3063792D1 (en) | 1983-07-28 |
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