FR2677120A1 - Device for photometric measurements based on optical fibres, and apparatuses equipped with such a device - Google Patents

Abstract

Device for photometric measurements based on optical fibres, in multiple beams or/and multiple wavelengths or/and in a single beam with black detection, and apparatuses equipped with such a device. The invention consists in directly illuminating the fibres (2) and (3) with a source (7) via an optical chopper or splitter (9), and/or a wavelength selector (9). This device also makes it possible to collect the corresponding beams on a reduced number of fibres (5) after passage through the samples (19), (20). An instantaneous choice can optionally be carried out between an internal measurement and a measurement on optical fibres. Main advantages: gain in light energy, sensitivity, resolution; without forgetting the possibility of using several remote sample holders, or of carrying out multibeam or/and multiwavelength, or fluorescence, phosphorescence, etc. measurements using a single detector (6).

Description

PHOTOMETRIC MEASUREMENT DEVICE BASED ON OPTICAL FIBERS,
AND APPARATUSES EQUIPPED WITH SUCH A DEVICE
The present invention relates to a photometric measurement device based on optical fibers, such as the devices which are fitted in particular to photometers or spectrophotometers.

This invention can be used for all types of photometric principle measurements, such as spectrophotometric, colorimetric, fluorimetric, nephelometric, polarimetric, reflectometric, opacimetric, turbidimetric, phosphorescence or diffusion measurements, etc.

It is known that photometric principle measuring devices, such as those detailed above, can be equipped with optical fibers if one wants to examine samples remotely in a sample holder or "in-situ" measurement compartment that the 'we will qualify as "distant", or directly in a pipeline or on samples using a fiber end sensor. If fibers are not available, the sample (s) must be brought to the measuring device to check them.

These photometric type measuring devices carry out absorption, emission, re-emission, reflection, etc. measurements of light at certain wavelengths, generally for the purpose of determining the presence of certain substances. in the samples, and to dose them. For this, the light output from the samples must be quantified as a function of the wavelength, or at least at specific wavelengths.

Let us take the particular case of spectrophotometers: either the sample is illuminated in white (or polychromatic) light, the beam then passing through a monochromator which makes it possible to select the wavelengths, or on the contrary the monochromatic light is created before the crossing of the sample.

Still in the case of the spectrophotometer, if optical fibers are not used, the sample is placed in a compartment inside the apparatus, so that this sample is crossed by the light flux. A "blank" can possibly be simultaneously measured in the case of the use of a double-beam spectrophotometers. We then deduce the light transmission curve (possibly differential) of the sample, or at least its transmission at one or more wavelengths.

Unfortunately, in certain cases, one cannot or does not wish to transport the sample to the apparatus, for example because the sample is radioactive, or toxic, or even dangerous to transport, or simply that one wish to make an In-Situ check. In this case, one or more optical fibers can make it possible to convey the light to the sample, then to collect the light leaving the samples, and to bring it back to a detector.

However, the use of optical fibers generally induces considerable energy losses, which is contrary to the efforts lavished to obtain a maximum of energy, therefore a maximum of sensitivity.

Recall that a decrease in light energy systematically means a loss of sensitivity, an obligation to open the slits (increase the bandwidth) to recover more energy therefore a loss of resolution, and finally a loss of linearity in absorbances high. The loss of light energy is therefore particularly harmful to the quality of the measurements.

One can achieve correct measurements in single-beam spectrophotometry, since in principle no energy is lost to create other beams: the energy loss dQe to the fibers is then acceptable.

However, the permanent measurement of the device's dark current by optical chopper is avoided, since this process causes a significant part of the energy to be lost.

If one wants to work in double-beam, one encounters significant difficulties, this for several reasons listed below.

On the one hand, double-beam measurements are generally made with a basic energy loss of 50 to 75%, even 85%, mainly due to optical division. This loss of energy is already considerable by itself, and it would add up with the loss of energy due to optical fibers, to leave in the end a very low energy, with which one can hardly obtain good sensitivities to weak absorbances and good linearity with high absorbances.

On the other hand, in double-beam spectrophotometers, the same beam is generally sent alternately on two so-called measurement and reference channels, respectively. Now if we want to recover this same beam to send it alternately on fibers respectively called measurement and reference, whether using an optical chopper, a set of mirrors or a device arbitrary, we are faced with two difficulties: the small size of the fiber entry, and the non-correspondence with the shape of the spot. The only simple solution would be to use a static optical divider, which would further divide the energy by the number of fibers to be illuminated ...

In addition, the fiber input acceptance cone is not used by solutions of this type, since a beam of given geometry is then recovered, much smaller in solid angle than what the fibers can accommodate.

In the same way, the entry of the fibers is indifferent & the position of the source which lights it: we can therefore use a reflector lamp without affecting the final resolution and recovering a very important energy, while such a lamp should be avoided at the input of a spectrophotometer, and such energy could therefore in no case be recovered from the fibers if they were successively illuminated with the beam which would normally have passed through the measurement and reference channels of the apparatus.

Likewise, if the light bulb burns out, it is generally necessary to replace it, which usually has to be done by competent people, and therefore poses problems during night-time handling by unqualified personnel.

Another drawback is the lack of flexibility of existing instruments. Generally, either a device is designed for use without fibers, or it is designed for use with fibers. A coupler formula to be installed in the internal tank holder exists, which collects the light supposed to arrive on the tanks: but it takes a long time to install, the energy losses are too great to meet sensitivity requirements, and we does not take advantage of any of the advantages of optical fibers; in fact only the disadvantages are suffered.

Finally, it is physically difficult to conserve satisfactory energy with two or more beams coming from different fibers when it is desired to recover them on a receiver or in a single monochromator, this in a balanced manner and without excessive energy losses.

The existing double-beam assemblies are generally simple couplers to be placed in the sample holder of a spectrophotometer, but whose performance leaves something to be desired, mainly due to the loss of energy.

In addition, remote double-beam measurements must be made using a spectrophotometer itself with a double beam, even if the internal rack of the spectrophotometer is not used.

Most of the assemblies existing on the market are therefore carried out on single-beam devices.

However, double-beam measurements have considerable advantages which it is useless to recall here, and which we cannot therefore - or misuse - with optical fibers.

By the present invention, it is proposed to best remedy these drawbacks. The invention aims to allow remote measurements using optical fibers by recovering maximum energy.

Another advantage consists in distributing the light coming from the two beams in a homogeneous way during their recovery in the measuring device, and & obtaining a good balancing on the various beams.

It is also possible to use the measuring device with sufficiently fine slots while losing a minimum of energy.

It will also be possible to carry out single-beam measurements with permanent detection of the dark current, or black (for example in single-beam spectrophotometry, in fluorimetry, etc.) while having optimum energy.

The use of the invention in some of its forms also saves a certain number of optical fibers. In particular, for double-beam spectrophotometry, one in four optical fibers is saved, which in addition means significant savings.

The design of the fiber illumination system also makes it possible, if a failure occurs at a source, to immediately select a backup source and continue the analyzes without calling on qualified operators to replace and adjust the source, or his diet.

Likewise, if desired, two or more additional optical fibers can be connected to the power supply unit, which makes it possible to make measurements on two or more photometers, with two or more independent so-called remote sample holders, while n 'having only a feeder: this allows significant savings.

In the same vein, a single fiber supply unit can supply several remote sample holders, and the recovered light fluxes can be recovered by the same measuring device, by selecting the corresponding input, for example at using a rotating mirror.

Another energy gain is also due to the shape of the signal generated by the optical chopper of the invention: in fact, the fiber input surface being very small, the sides of the signals detected on the photomultiplier or the detector Photoelectric or optoelectronic are very clear, unlike the conventional aspects of the signals generated by the chopping of a large light spot, for which the time necessary between the free passage of the spot and its complete closure by the disc is important. We can thus easily gain directly from 10 to 20% of energy. In addition, we can reduce the shutter zones since obtaining black is instantaneous: we can therefore enlarge the zones allowing each beam to pass over the chopper disc, and gain 15 to 25% more energy. So on two tables: first the "flank" areas replaced by a full signal, then the possibility of extending the measurement time of each signal.

In addition, special lamps can be used in the fiber supply box ", and fitted with heat filters and / or water filters, as well as specific filters. This would be difficult to achieve in a measuring device such as a spectrophotometer, significant thermal releases would interfere with its operation, and the space would be considerable.

Finally, one of the forms of the invention makes it possible to instantly choose between a measurement inside the device and an in-situ measurement by optical fibers, since the optical fiber system creates a beam entering the spectrophotometer as would that of a lamp. We can therefore choose between the spectrophotometer lamp, which allows analysis in the internal sample holder, or the light beam created by the fiber device, equivalent to a second lamp.

In addition, a simple single-beam spectrophotometer can be used as a final detector, or even a simple photomultiplier detector, even if you want to make double or multi-beam measurements. Indeed, the invention by itself may already include the optical divider and its synchronization, which makes the internal chopper of the spectrophotometer unnecessary, as well as the selection of wavelengths, which makes an internal monochromator unnecessary. This also allows significant savings.

Likewise, measurements of fluorescence, phosphorescence, etc.

can be carried out with a simple detector at the end of the chain (even a simple photomultiplier), as we will see later, the device & fibers giving & alone these functions.

Similarly, optical filters can be inserted alternately in front of the fibers, for example by fixing them in front of certain orifices of the chopper: multi-wavelength measurements are then obtained.

The invention therefore relates to an analysis device using optical fibers, double-beam, multi-beam, multi-wavelength or even single-beam with black detection, characterized in that the illumination of the fibers leaving towards the so-called remote sample holder (s) or measurement system is done directly by one or more lamp (s) or light source (s), and the optical division is immediately carried out by a optical divider at the very entrance of these fibers.

We can thus make the most of the fiber acceptance cone by illuminating them directly using a lamp, in a box that we will call fiber supply box ", this boot may or may not be an integral part of the spectrophotometer The use of a reflector lamp is very advantageous here, whereas it would be to be avoided at the entrance of a monochromator for which one would create several virtual objects, therefore an astigmatism or optical nuisances.

We then recover a considerable solid angle of illumination by the filament (or arc) of the lamp, to inject it into the fibers. In addition, the fibers are illuminated by the same source or sources, which makes it possible to overcome, by differential measurements, any drifts of the source or sources.

In addition, double-beam measurements can be carried out in the so-called remote sample holder while only having a single-beam spectrophotometer, since optical division and synchronization are ensured at the device & fiber level.

Advantageously, if the optical division is carried out in the "fiber feed box" by a rotary chopper, a simple and reliable system, a very clear signal is obtained, with almost vertical sides, instead of having a conventional form of slots with inclined sides due to the size of the light beam cut by the chopper. We thus gain signal (the flanks are replaced by a full signal) and we can reduce the shutter zones (since the black is instantaneous as of shutter), therefore increase the areas of passage of the beams, therefore further increase the energy and the sensibility.

The measurement of the dark current is also better than if it was blocked in the measuring device, because we then take into account stray lights that can be introduced into the remote sample holder (s) or remote analysis systems, which is not the case with a shutter located in the measuring device.

Another advantage is to expose each fiber only part of the time (while causing additional local ventilation if the rotating disc is close enough to the fibers), which allows to illuminate the fiber (s) with more powerful sources. without damaging them.

Advantageously, to carry out measurements in double-beam spectrophotometry, the optical chopper alternately illuminates two fiber ends, which themselves will illuminate at their output two so-called measurement and reference samples, respectively.

Advantageously, the rotary disc can be provided with filters, and thus successively select wavelengths on one or more fibers, making it possible to carry out multi-wavelength measurements while retaining the possibility of permanent measurement of black.

Advantageously, the two preceding possibilities can be combined, and the disc can successively allow the illumination of certain fibers while closing others, the orifices allowing the light to pass through being able to be fitted with filters, which makes it possible to carry out multi measurements. -wavelengths and multi-beams.

Advantageously, in the remote sample holder, the light coming from these two fibers (or from several fibers) can be collected after the passage of the samples on a single fiber (or on a certain number of output fibers), for example & l using mirrors, or simply by collecting certain beams at their intersection on an output fiber, or by illuminating for example two output fibers & BR <from a received beam.

There are many advantages: if the final measurement is made by a single detector or measuring device, it is in your interest to reduce as much as possible the section of the output fiber (or the total section of the output fibers), and you gain d '' all the more in resolution in case the fiber collecting the exit beams would in turn direct the light which leaves towards the entry of a monochromator, since one can narrow the entry slit of the monochromator by recovering almost all light energy (small image).

Conversely, if one wishes to carry out measurements on several detectors or measuring devices at the same time, one may wish to collect on several fibers the same light signal coming from a sample, in which case one may wish to have more fibers leaving the sample holder.

We can also have as many fiber ends at the inlet as at the outlet, and wish to group the outlet fibers into a single one, if these are multi-stranded.

Advantageously, if we analyze phenomena of the emissive, or reflective, or diffusive type, or any phenomenon of emission or re-emission of light by the sample, an identical solution & the previous one can be retained.

Advantageously, if one wishes to carry out double-beam measurements, the beams from the two fibers which illuminate the so-called reference and measurement samples in the so-called remote sample holder are grouped on a single output fiber, which makes it possible to gain 50% total surface area of output fibers (gain in resolution of the spectrophotometer input), as well as the short of a second output fiber.

Advantageously, the light coming from the fiber which finally arrives in the measuring device or on the detector is projected onto the entry slit of the device or onto the detector. For example in the case of a spectrophotometer, this arrival of light will play the same role as the light beam coming from a lamp.

Advantageously, the output fiber is of the multi-strand type, so that the output image can take the form of a slit, and be projected onto the input slit of a monochromator without undergoing the losses of energy that would have created, for example, the projection of a luminous disc on a slit.

Advantageously, the projection is done in a photometric measuring device or detector (which can even be very simple) and the characteristics of the type of measurement will be determined by the device & optical fibers. More clearly, using examples, double-beam or multi-wavelength measurements can be carried out with a simple single-beam spectrophotometer, or fluorescence detections can be made by always using a single-beam spectrophotometer as the final measuring device: it is the conformation of the "fiber supply box and the so-called remote sample holder which will function. We can even carry out multi-wavelength and / or multi-beam acquisitions with a simple detector without monochromator.

Advantageously, the projection can be done on the input of the monochromator of a double-beam spectrophotometer, itself having an internal optical chopper. synchronization can then either be done on the optical chopper of the fiber device (by stopping the internal chopper of the spectrophotometer, in which case the measurements are carried out remotely), or on the internal chopper by switching to a lamp (in which case the measurements are inside the spectrophotometer, in its sample holder compartment). The fiber arriving in the spectrophotometer becomes the equivalent of a second lamp of the spectrophotometer, and the switching between these two sources is instantaneous, without any assembly or disassembly.

In addition, in case of doubt about the operation in fiber mode, a switch can be made on the internal rack, which allows immediate verification of the measurement chain.

Advantageously, the "fiber supply case" in which the fibers are illuminated and the optical division can be equipped with several sources and / or several power supplies and / or several optical dividers, choppers or wavelength selectors . It is thus possible to have several so-called remote sample holders or so-called remote analysis systems with a single (or several) photometric measuring device or sensor, or else choose to keep the outputs of the "fiber feed box" free. to have emergency lights in the event of failure of one of the lighting devices.

Advantageously, if it is desired to make double-beam spectrophotometric measurements, two sources (possibly with their two respective power supplies) can be placed in front of the chopper, in diametrically opposite manner. Thus, if the lamp used comes to burn out (or its power supply), the operator can decide to use another lamp without having to make any adjustments, simply by placing the set of fibers in front of the other source. Likewise, the second lamp provided with its own power supply can be used to power another set of fibers, therefore another sample holder and possibly another spectrophotometer.

Advantageously, the 2'bottier for feeding fibers "can be equipped with special lamps, for example for the infrared, and possibly be provided with anti-heat filters and / or with a circulation of water, in order to to get better sensitivity at certain wavelengths. This could hardly be done in the spectrophotometer itself, due to thermal and bulk problems.

The invention also relates to a photometric measuring device equipped with such a servo device, whether externally as indicated in the examples of diagrams which follow, whether semi-externally by integrating a part of the functionalities and leaving one or other parts external, or whether it is in an integrated manner, that is to say that all of the relative functionalities & BR <the invention have been integrated in the same measuring device , which would then be similar to a normal measuring device, the so-called remote sample holder then being the internal rack of the instrument.

The invention will be better understood with the aid of the detailed description which follows, given with reference to the appended drawings, these drawings and these descriptions being relative to a particular embodiment and being in no way limiting.

FIG. 1 is a partial internal diagram of a measurement device according to the invention, in the particular case of spectrophotometric double-beam measurements.

FIG. 2 is a block diagram in external view of a complete measurement device according to the invention, in the case of double-beam measurements.

FIG. 3 represents a possible diagram of the internal organization of the "fiber supply box", in the case of double-beam measurements.

FIG. 4 represents a top view of the interior of this same box, in the case where two light sources are placed, capable of illuminating two sets of fibers or else a set of fibers with emergency lighting, still in the case of double-beam measurements.

Figures 5, 6, 7 and 8 show examples of remote measurement compartments: - in Figure 5, the two beams from the two fibers arriving in the sample holder are grouped by two mirrors - in Figure 6, the two beams naturally group together - in Figure 7, we see a device suitable for carrying out fluorescence measurements - in Figure 8, the output fiber of the multi-strand type groups together into a single fiber
FIG. 9 represents an example of entry into the monochromator of a spectrophotometer
FIGS. 10 and 11 show the conventional signals obtained by an internal chopper in a double-beam spectrophotometer, to be compared with the signal obtained using the invention.

FIG. 12 shows the signal which can be obtained after modification of the chopper, taking account of the observations of FIGS. 10 and 11.

FIG. 1 shows the partial internal diagram of a measurement device according to the invention, in a particular case of double-beam measurements. A lamp (7) illuminates through a rotary optical chopper (9) two fiber tips (2) and (3), the opposite ends of which in turn illuminate two samples, respectively of measurement (19) and of reference (20), located in a so-called remote sample holder (4). The light coming from these samples is gathered on a single fiber (5), which finally reinjects this light into the detector, the measuring device or the spectrophotometer (6).

In Figure 2 is shown the overall diagram of a complete measuring device equipped with the invention, in the case of double-beam measurements. We can distinguish the box used for the illumination of the fibers (1), called "fiber supply box", from which two optical fibers (2) and (3) leave, the so-called remote sample holder (4) where placed the samples to be analyzed, an optical fiber (5) output from the so-called remote sample holder, which leads to the entry of a measuring device, simple detector, spectrophotometer or any type of device with photometric principle (6) .

The interior of the "fiber supply box" can be better analyzed using the example in FIG. 3, which always corresponds to double-beam measurements. A reflector lamp (7) which, in this particular case, is the light source, is supplied by its power supply unit (8), which illuminates the ends of two optical fibers (2) and (3) through a rotating disc (9) called an optical chopper, often called by anglicism: chopper, and which has orifices which allow light to pass alternately through one or other of the fibers. The shutter periods of the two beams can allow the measurement of the device's dark current.

Each of the fiber tips is opposite a corresponding track of the disc, respectively (10) and (11). The disc is rotated by a motor (12), directly or by means of a belt. Its rotation is controlled by a so-called synchronization signal emitted by an optoelectronic detector (13), itself placed on a so-called synchronization track (14), also provided with orifices, which makes it possible to know at all times that it is the illuminated fiber, and what are the shutter phases. Four phases follow one another permanently: -Fiber (2) lit, fiber (3) not lit -Fiber (2) not lit, fiber (3) not lit -Fiber ( 3) lit, fiber (2) not lit - Fiber (2) not lit, fiber (3) not lit
We therefore recreated at the output of the fibers (2) and (3) an alternation equivalent to that of the measurement compartment of a double-beam spectrophotometer.

FIG. 4 also represents the interior of the "fiber supply box", with an additional set of fibers (17) and (18), illuminated by a source (15) provided with its supply (16). Obviously, this source (15) can serve as security (in the event of a failure of an illumination device) if we only use one set of fibers, in which case it is enough to place our set of fibers in front emergency lighting to continue measurements without having to change the lamp or find the cause of the failure.

FIG. 5 shows the interior of an example of a so-called remote sample holder, still in the case of double-beam measurements. The fibers (2) and (3) respectively illuminate the samples (19) and (20), the light being transformed by means of lenses or devices & lenses called "condensers", or even specific optical systems. The last two condensers (or lenses) crossed by each beam are such that they form an image & infinity, the two beams being reflected by two mirrors (21) and (22).

We can then, using a lens, a condenser, or another type of optical device, reform a single image of the two beams on the input of a last fiber (5), if for example the input of this fiber is placed at the focal distance of the last optical system. The two mirrors (21) and (22) can possibly be grouped in an aluminized prism.

FIG. 6 represents the same so-called remote sample holder, with a "natural" grouping of the two beams. The numbers correspond to the descriptions in Figure 4.

FIG. 7 also represents the so-called remote sample holder, but in the case of a fluorescence measurement.

The sample to be examined (19) is excited by the fiber (2), and the fluorescence is collected at 900 by the fiber (5).

In FIG. 8, we see a system close to those of FIGS. 4 and 5, but where the light leaving the two input fibers (2) and (3) are sent after passing through the two samples (19) and (20 ) on the ends (5.1) and (5.2) of two multi-strand fibers, grouping into a single fiber (5).

FIG. 9 shows an example of projection in the spectrophotometer, with an example of a rectangular fiber tip (23) seen from the front. It can be seen that the image of this tip is projected through the optical system (24) into the entry slit of the spectrophotometer (25) without loss of energy.

FIGS. 10 and 11 respectively represent the shapes of the signals which can be obtained with the internal chopper of the spectrophotometer, and with the external chopper of the fiber device, this again in the case of double-beam spectrophotometry. Zones A represent the passage of light in the so-called measurement sample, while zones B represent the passage of light in the so-called reference sample. The zones O correspond to the obturation of the two beams, and the zones N correspond to the real obtaining of the dark current on the photodetector.

First of all, it can be seen that with the chopper of the invention, the flanks are very clear, and that an additional signal portion (26) is recovered compared to the conventional chopper
In addition, it can be seen that with the conventional chopper, the dark areas differ greatly from the shutter areas of the two beams, this being mainly due to the size of the spot to be closed. We are then forced to shutter "long" to obtain a real black area N usable.

This no longer occurs with the chopper of the invention, which makes it possible to significantly reduce the shutter zones while keeping a valid black, as can be seen in FIG. 12. This thus increases the acquisition times of the zones A and B, so we gain a lot of energy.

Claims (18)

1) Device for photometric measurements based on optical fibers, carried out either in multi-beams, or in multi-wavelengths, or in single-beam with possible detection of black, and concerning all types of colorimetric, spectrophotometric, reflectometric measurements, fluorimetric, nephelometric, polarimetric, or any other type which is based on a photometric measurement, characterized in that the optical fiber (s) is or are directly illuminated by a light source, by the through an optical divider or a wavelength selector, or an optical chopper. 2) Device according to claim 1, characterized in that the optical divider is a rotating disc, alternately letting the light source illuminate one or more fibers, simultaneously, alternately or independently, while possibly closing others. 3) Device according to claim 2, characterized in that the optical chopper alternately illuminates the ends of the two fibers of a photometric & double-beam measurement device, each going to illuminate & its output samples respectively called measurement sample and reference sample, in a sample holder or so-called remote analysis system. 4) Device according to claim 1, characterized in that the wavelength selector is a rotary disc having one or more opening (s) which can be provided (s) with light filters, allowing to select alternately or simultaneously on a or more fibers the wavelengths or wavelength ranges corresponding to the filters used. 5) Device according to claim 1, characterized in that the optical divider used to create the multi-beam (or the monobeam with black detection) is at the same time equipped with filters used to select wavelengths or ranges of wavelengths, which makes it possible to carry out instantaneous analyzes in mono, double or multi-beams with several wavelengths, in one or more sample holder (s) said (s) remote (s) or system (s) d analysis said (s) distant (s). 6) Device according to any one of the preceding claims, characterized in that the light coming from the ends of the different fibers and entering a sample holder or so-called remote analysis system is grouped together at the output of this sample holder or so-called remote analysis on one or more output fibers. 7) Device according to any one of the preceding claims, characterized in that the light emitted, re-emitted, reflected, scattered or diffracted by the samples in a sample holder or so-called remote analysis system is grouped at the output of this sample holder or so-called remote analysis system on one or more output fibers. 8) Device according to claim 6 or claim 7, characterized in that the so-called remote sample holder or said remote measurement system relates to double-beam photometric measurements, and that the beams from two fibers respectively illuminating two samples so-called measurement and reference, are grouped on a single output fiber. 9) Device according to any one of the preceding claims, characterized in that the arrival of the light signal in the final detector or final measuring device (the photometer, or the fluorimeter, the polarimeter, the colorimeter, the nephelometer, the spectrophotometer , etc ...) is done by the projection on the input slot of the monochromator (possibly through an optical system) of the light spot of fiber exit, this fiber exit playing then a role equivalent to that which would play a second lamp in a spectrophotometer. 10) Device according to claim 9, characterized in that the fiber entering the final detector or final measuring device (photometer, or fluorimeter, reflectometer, polarimeter, colorimeter, spectrophotometer, etc.) is of the multi-strand type and that the illuminating part of its exit is rectangular or elongated, its projection on the entry slit of the spectrophotometer then allowing a minimum of energy loss thanks to its shape similar to that of the possible entry slit of the measuring device. 11) Device according to any one of the preceding claims, characterized in that the type of final measurement carried out (double-beam, fluorescence, reflectance, etc.) is carried out by a final measurement device which does not itself have these functionality, but serving as a detector. 12) Device according to claim 11, characterized in that several fiber devices allowing identical or different functionalities arrive on the same measuring device or simple detector, thus making it possible to carry out with a single inexpensive device several types of measurements. 13) Device according to claim 11 or claim 12, characterized in that all of the acquisitions are carried out on one or more spectrophotometer (s) & single beam, the invention ensuring & it alone optical division and synchronization, therefore the double-beam, multi-beam, multi-wavelength, fluorimetry, etc. measurement in the door (s)  so-called distant samples. 14) Device according to any one of the preceding claims, characterized in that the internal optical chopper of the spectrophotometer can stop in a determined position and then let the double-beam synchronize on the optical chopper of the device & fibers optics, or synchronize with the chopper of the fiber optic device, allowing instant choice between a measurement inside the spectrophotometer, or outside (using optical fibers) in the sample holder (s) ( said remote. 15) Device according to any one of the preceding claims, characterized in that another or other device (s) for illuminating fibers is or are present (s) in front of one or more optical divider (s) ) or wavelength selectors, and allows (tent) either to illuminate several sets of fibers for measurements in other so-called remote sample holders or so-called remote measurement systems, with other spectrophotometers or with the same spectrophotometer using another or other lamp input (s), either to have emergency lighting for one or more sets of fibers in the event of failure of lamp (s) or power (s) . 16) Device according to claim 15, characterized in that two fiber illumination devices (sources and their respective supplies) are present in front of a rotary optical chopper or the wavelength selector, diametrically opposite, in order to be able quickly extract the fibers and re-insert them in the other location opposite the other lighting device in the event of a failure of one of the feeding devices, or on the contrary in order to permanently use two sets of fibers to make measurements in two so-called remote sample holders, with two spectrophotometers or simply on two lamp inputs of the same spectrophotometer. 17) Device according to any one of the preceding claims, characterized in that the measurement is carried out simply using a detector without a monochromator, the selection of the wavelengths being carried out directly from the illumination device, which allows remote single or multi-wavelength analyzes. 18) Measuring device or set of devices using a fiber-optic measurement device such as one of the devices described in one of the preceding claims, each of these parts possibly being external or not, the door or doors - so-called remote samples that can be really remote or, on the contrary, integrated into the device or the set of devices, as well as the power supply unit (s) fibers.