AT510630A1 - SPECTROMETER - Google Patents

Abstract

The invention relates to a spectrometer (1) for examining the constituents of a fluid (2), comprising a housing (3) with a light source (4) arranged therein and a detector (5) arranged therein, the light from the light source (4) passing through a transmission window (7) along a predetermined path length (x) through the fluid to be examined (2) and through a receiving window (8) to the detector (5) is guided. For simple conversion of the spectrometer (1) to different path lengths (x) is at least one insert (10) with a passage channel (11) for the light beam and at least one window (12) for arrangement in front of the transmission window (7) and / or Receiving window (8) for shortening the path length (x) provided.

Description

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The invention relates to a spectrometer for examining the constituents of a fluid having a housing with a light source arranged therein and a detector therein, wherein the light of the light source is guided through a transmission window along a predetermined path length through the fluid to be examined and through a receiving window to the detector.

The spectrometer may include one or more light sources and also one or more detectors. In spectroscopy, the intensity of the emitted light is reduced by certain ingredients of the fluid to be measured and inferred by the detection of the intensity of the received light with knowledge of the intensity of the emitted light on the concentration of the ingredient. Different ingredients have different absorption properties and have optimal absorption properties at different wavelengths of light. Accordingly, there are certain suitable wavelengths for the detection of certain ingredients. By emitting light with a broader wavelength range, the concentrations of several ingredients in the fluid to be examined can also be carried out at the same time. For example, flash lamps are particularly suitable.

In order to achieve suitable measurement results, the maintenance of certain absorption ranges is appropriate. Depending on the nature of the fluid to be examined and the nature of the substance to be examined, different path lengths, ie those lengths over which the light passes through the fluid to be examined, are required or advantageous for the maintenance of these absorption regions. Usually, different spectrometers with different path lengths are used, depending on the bulkiness of the fluid to be examined and the quantity of inhalables to be measured. This means for the user an increased cost but also OrgsnisaLionsaufwand.

In the prior art, spectrometers have become known, which have variable path lengths. Example 5we-j_se describes - 2 - # · ΙΜ I * «·· Φ * *« · * • · • # * 1 US 5 168 367 A such a spectrometer. However, the construction is relatively complex and error-prone, since the path length must be set correctly by the user and checked by appropriate gauges.

A construction of a spectrometer with several path lengths has become known, for example, from US Pat. No. 6,643,016 B2. This construction is characterized by a relatively complicated construction unc in consequence of increased costs.

The object of the present invention is therefore to provide an abovementioned spectrometer in which the path length for adaptation to the fluid to be investigated or the ingredient to be examined can be easily changed. The cost of the spectrometer should be as low as possible and the change in the path length should be possible quickly and easily. Disadvantages of known spectrometers should be avoided or at least reduced.

This object is achieved in that at least ei.n use with a Durchl.rittskanal for the. Light beam and at least one window for arrangement in front of the transmission window and / or the Hmp fanqsfenster is provided to shorten the path length. The subject invention thus provides at least one insert, which is arranged in front of the transmission window and / or receiving window of the spectrometer and correspondingly shortens the path length. Thus, adaptation of the spectrometer to changed conditions is particularly easy and simply possible. The user only has to purchase the insert or multiple inserts and not have another spectrometer with changed path length. Of course, the at least one use reduces the transmission of the Li cht.Strahls, but this can be easily corrected by appropriate increase in the intensity of the light source. Assuming a corresponding construction of the spectrometer and the at least one insert, the cost of changing the path length is particularly low and can be carried out particularly quickly.

Advantageously, an insert is provided in front of the transmission window 3 and in front of the reception window for shortening the path length.

If the inserts are identically constructed, the manufacturing costs thereof can be reduced and mis-assembly by the user can be avoided.

According to a preferred embodiment of the insert, a seal, preferably a sealing ring made of elastic, is provided on the side facing the transmission window or receiving window of the spectrometer. Material, provided. The optical path length shortening insert is simply placed over the transmission window or reception window of the spectrometer and the passageway sealed by the seal against the fluid. Thus, the beam of light in the area between the transmitting or receiving window and the window in use is not affected, which could lead to measurement errors. In the simplest way, the seal is formed by a corresponding sealing strip or sealing bead, which is arranged in a groove on the end wall of the insert, or by a 0-R.ing. U: r. To prevent corrosion of the insert, in particular in Spektrometersonden, which are introduced or immersed in the fluid to be measured, it is advantageous if each insert is made of stainless steel. In addition, it is advantageous if the inserts have no edges or corners to which impurities could accumulate. For certain applications, it is of course also possible to manufacture the inserts made of other metals or plastic.

In the case of spectrometers, which are immersed in a liquid to be measured and the ingredients to be examined "in situ". It is customary to clean the transmission window and the reception window at regular intervals. For this purpose, nozzles are arranged on the spectrometer, which direct a rinsing liquid or purging air on the Sendeienstei and receiving window and thereby remove impurities from the surface. If the optical path length is changed by at least one insert, it is expedient or necessary to determine the direction of the rinsing liquid or purging air.

t back to. Ser.cef now he or receiving window now to change the window in the insert. Expediently, so-called flushing stones with flushing channels for guiding the flushing liquid or flushing air for flushing the transmission window and the reception window are provided for this purpose in the spectrometer. These purging blocks are preferably provided with flushing channels adapted to the inserts used. Depending on the path length of the angle of the flushing channels is changed accordingly to direct the jet of rinsing liquid or purging air exactly to the respective window to be cleaned.

In order to further reduce the assembly effort for changing the path length, the inserts may at best be made in one piece with the purging plug. Thus, it is only necessary for the user to attach a component to the spectrometer or to dismantle.

Advantageously, a set of different inserts and possibly different rinsing stones for different path lengths is provided. For example, missions can be used to obtain path: änqer. of 3 5, j ::>, 5, 2, 1 and 0.5 mm. The largest fading length is used with a very clear medium, for example drinking water, and the smallest path length with a visually very dense medium or a medium with a high substance concentration, in order to be able to achieve the required absorption range for the spectrometric measurement. 'In the wrong monr.ager. To avoid, the various can. Inserts have a coding. Such coding can be realized in the simplest case by a mere color coding or by numbers on the inserts and possibly purging stones up to electronic coding, for example by RFID (Radio Fre- quency Idenr.iticatior.) Transponder, which also ei ne auto -ir.ati see Anoassunc allow the intensity of the light source of Spekironeters.

The present invention will now be explained in more detail with reference to the attached drawings. I * * * * * * * «« * 4 4 * * * · * * * ·

Show in it

Fig. 1 shows a basic structure of a spectrometer;

Fi q. FIG. 2 is a perspective view of a section of a spectrometer probe with two inserts according to the invention for shortening the path length; FIG.

Fig. 3 shows the embodiment of FIG. 2 with: dismantled inserts, in side view;

FIG. 4 shows the embodiment according to FIG. 3 in plan view;

5a to 5b show different views of an embodiment of an insert for shortening the path length; and

Fig. 6a to 6d different views on a replaceable flushing stone.

Fig. 1 shows the basic structure of a spectrometer 1, in particular a spokzroxetrischen probe, which is introduced or immersed in the fluid 2 to be examined. Within a housing 3, at least one light source 4 and at least one detector 5 are arranged. The light of the light source 4 is possibly directed via an optical system 6 through a transmission window 7 in the fluid to be examined 2 and a Kmpfangsfenster 8 and all due optics 9 to the detector 5. From the difference between the intensity of the light received by the detector β and the intensity of the light emitted by the light source 4, it is possible to deduce the concentration of certain contents in the fluid 2. The fluid 2 is transilluminated along the Pfadlängc Ax from the transmitting window 7 to the receiving window 8 from the light.

By reference to the so-called Zwo 1-beam measuring method, a reference light beam outside the fluid 2 in the housing 3 is sent parallel to the Moss beam between the transmitting window 7 and the receiving window 8 to the detector b. For certain fluids 2 and for the determination of particular ingredients, different pathogenic Δχ are useful. While, for example, a very long path length Δχ is possible for very clear drinking water, the path length Δχ for visually very dense media or media with a very high substance concentration must be significantly lower in order to achieve optimum measurement results.

2, 3 and 4 show a detail of an embodiment variant of a spectrometer 1 in which the path length Δχ is shortened by two inserts 10. The inserts 10, which in the illustrated embodiment, on both sides, i. are arranged both on the side of the transmitting sensor 7 and on the side of the receiving window 8 of the spectrometer 1, comprise a passageway 11 for the light beam and at least one window 12, which are arranged in a corresponding housing, preferably made of stainless steel. The insert 10 is anoeordnei before the transmission window 7 or receiving window 8 such that the originating from the transmission window 7 light through the. Passage channel 11 of the insert 10 and the window 12 can get into the fluid to be measured 2 and then passes through the window 12 and the Lurchtrittskanal 11 of the second insert IC in the receiving window 8 of the spectrometer 1 and the detector 5. With the help of appropriate fasteners, especially screwdrivers. 1.3, the inserts 10 are attached to the housing 3 of the spectrometer 1. In order to prevent the fluid 2 from entering the passageway 1 " the insert 10 passes and there leads to measurement errors, is on the transmitting window 7 or 8 receiving window 8 facing side ries insert 10 preferably a seal 14, for example in the form of an O-ring arranged. By arranging such inserts 10, the path length Δχ can thus be reduced correspondingly to a smaller path length Δχ '. The assembly of the inserts 10 is particularly quick and easy to carry out. Instead of screws 13 and other Befesligungsclemente can be used, for example, zuiassen a tool-free assembly and disassembly.

5a to 5c show various views of an embodiment of an insert 10. FIG. 3a shows a perspective view of an embodiment of an insert 10 obliquely from the front onto the window 12. FIG. 5b shows a perspective view the insert 10 of FIG. 5a from the back, which is. those in front of the broadcasting window

Side with the insert 10 in front of the transmitting window 7 and receiving window 8 of the spectrometer 1 is placed. Fig. 5c shows a view of the insert 10 from the front, i. to the side with the window 12, Fi.g. 5d shows a section through the insert 10 according to FIG. 5c along the section line A-A and FIG. 5e shows a section through the insert 10 according to FIG. 5c along the section line B-B. The insert 10 includes the passageway 11, the window 12 and two holes 15 for receiving the screws 13 (see FIG. 3). The holes 15 are preferably arranged obliquely to ensure optimum attachment of the insert 10 on the housing 3 of the spectrometer .1. The window 12, which consists in particular of sapphire glass, is pressed or glued in the insert 10. To achieve different path lengths Δχ different inserts 10 may be provided with different dimensions. These can be color-coded, for example, to make the application particularly easy for the user.

The two sides, i. before the. Transmit window 7 and the receiving window 8 of the spectrometer 1, disordered inserts 10 may also be integrally produced (not shown).

Be · Spectrometers 1, which are arranged directly in the fluid to be examined 2, it is customary to clean the transmission window 7 and the receiving window 8 regularly. For a rinsing liquid or purge air is used, which is directed under appropriate pressure on the transmission window 7 and receiving window 8. The rinsing liquid or rinsing air is guided in rinsing channels 17, which are arranged in corresponding rinsing stones 16 on housing 3 of the spectrometer 1. Figures 6a to 6d show different views of an off f rur.as form of such a purging plug 16, as it can be disordered in a corresponding recess 16 in the housing 3 of the spectrometer 1 (see Figs. 3 and 4). 6a shows a perspective view of a sink 16 from the side facing the fluid 2 to be examined, FIG. 6b shows a perspective view of the sink 16 according to FIG. 6a from the lower side, FIG. 6c shows a view of the sink 16 according to FIG 6a from above, ie from the side facing the fluid 2 to be examined. Finally, FIG. 6d shows a sectional view through the sink 16 according to FIG. 6c along the section line B-3. The 8th

Sink 16, which is also preferably formed of stainless steel, has two holes 19 for receiving fasteners, such as screws (see Fig. 3), on. After in the arrangement of inserts 10 on the spectrometer 1 whose window 12 and not the original Transmitter 7 and receiving window 8 of the spectrometer l are to be cleaned, the purge 16 provides a correspondingly changed leadership of the purge duct 17 before. Preferably, 10 respective purging blocks 16 are provided to each of the corresponding inserts, which can also be offered in a corresponding set. Of course, the flushing blocks 16 may also be made in one piece together with the inserts 10 and thus be fastened even faster on the SpcktromcLer 1 and dismantled again.

The embodiments of the inserts 10 or sinks 16 are not limited to the illustrated examples. Important in the design of the inserts 10 for spectroscopic probes is, as far as possible, to avoid edges or corners on which dirt can be arranged.

The present invention provides a simple and inexpensive way to quickly and easily disfigure a spectrometer 1 for measuring various contents of fluids 2 or for measurement in different fluids 2. The user does not need a multitude of differently constructed spectrometers 1 for the measurement of different contents or in different fluids 2.

Claims (11)

Claims 1. A spectrometer (1) for examining the contents of a fluid (2) comprising a housing (3) having a light source (4) and a detector (5) disposed therein, the light from the light source (4) passing through Transmission window (7) along a predetermined path length (Δχ) through the fluid to be examined (2) and through a receiving window (8) to the detector (5) is guided, characterized in that at least one insert (10) with a passage channel (11) for the light beam and at least one window (12) for arrangement in front of the transmission window (7) and / or the reception window (12) for shortening the path length (Δχ) is provided. 2. spectrometer (1) according to claim 1, characterized in that in each case an insert (10) in front of the transmitting window (7) and the receiving window (8) for shortening the path length (Δχ) is provided. 3. spectrometer (1) according to claim 2, characterized qeker.nzei chnet, that the inserts (10) are constructed identically. 4. spectrometer (1) according to claim 1 or 3, characterized in that each insert (10) on the transmission window (7) or receiving window (8) facing side with a seal (14), preferably a sealing ring made of elastic material provided is. 5. spectrometer (1) according to one of claims 1 to 4, characterized in that each insert (10) with at least one screw (13) on the housing (3) is fixed. 6. spectrometer (1) according to one of claims 1 to 5, characterized in that each insert (10) is formed of stainless steel. 7. spectrometer (1) according to one of claims 1 to 6, characterized in that a replaceable purging plug (16) with flushing channels (17) for guiding a rinsing liquid for purging the transmission window (7) and the receiving window (8) is provided. • »* · * *« «* * * * * *« · * - ··· t «· * * * 9 * 9« «% # * * * * * * - 10 - 8. spectrometer (1) according to claim 7, characterized in that rinsing stones (16) are adapted to the inserts used (10) flushing channels (17) are provided. 9. spectrometer (1) according to one of claims 1 to 8, characterized in that the inserts (10) at best with the sink (16) are made in one piece. 10. spectrometer (1) according to one of claims 1 to 9, characterized in that a set of different inserts (10) and possibly different rinsing stones (16) for different Pladlän gene (Δχ) is provided. 11. spectrometer (1) according to claim 10, characterized in that the different inserts (10) have a coding.