DE3210719A1 - Instrument for measuring the density of liquids - Google Patents

Abstract

Instruments for measuring the density of liquids or the concentration of a plurality of components of a liquid have a completely enclosed hollow glass body, which is weighted at its lower end and is provided with a scale and is known under the designation areometer, is based on Archimedes's principle and has undergone no fundamental changes since the times of Archimedes. Measurements are very laborious, and as a result densities and concentrations on the laboratory and industrial scale have been determined in the meantime by other methods. In order to modernise the measurement of densities or concentrations on the basis of Archimedes's principle, a congeneric instrument is to be extended and automated, so that accurate and largely automatic measurements are possible. To this end provision is made to arrange in the hollow glass body (4) a magnetisable body (8) oriented perpendicularly to the extension direction of the hollow glass body, at least one electromagnet (14) being arranged around a container (3), the coils of which electromagnet furthermore, as a function of the submersion of the glass tube (4), can have a current applied to them by means of an electronic unit (23). <IMAGE>

Description

0719

DR. INC. HANS LICHTI · DI PL.-NM G? * H ETN £ R LICHTI DIPL.-PHYS. DR. JOST LEMPERT PATENTANWÄLTE

D-7500 KARLSRUHE 41 (CrOTZINCEN) ■ DURLAC HER STR. 31 (HIGH-RISE)

TELEPHONE <072l> 48511

P 32 10 719.6 · August 10, 1982

Dr. Bernd Alber 6372 / S Le

Device for measuring the density of liquids

The invention relates to a device for measuring density of liquids, especially the concentration of the proportions of a liquid mixture, with one in its lower part weighted, elongated hollow glass body, in its direction of extension a measuring section is provided and with a container receiving the liquid to be examined.

Known such devices are in the design of a hollow glass body, which is weighted at its lower end and has a scale as a measuring section known as a hydrometer. The measurements with such hydrometers are based on the Archimedean principle and a Measuring by means of hydrometers has been around since the discovery of the Archimedes Principle has not been further developed in practice. Measuring using known hydrometers is cumbersome, time-consuming and often not accurate. Hence determining densities or concentrations of

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Liquids today using different measuring principles and devices carried out.

The invention is therefore based on the task of a more precise device for measuring the density or concentration of liquids to create, in particular, an accurate, practical and largely fully automatic measuring permitted.

According to the invention, the stated object is initially achieved by that in the hollow glass body an elongated, magnetizable body with an extension component directed perpendicular to the axis of the hollow glass body is arranged and that at least one electromagnet is arranged on the circumference of the container.

It is in principle possible with the magnetizable body get along in the hollow glass body if it is permanently pre-magnetized is; it will then turn north-south like a compass needle set as long as there are no other distracting iron parts or Magnets are in place. However, this requires that the other parts of the device and when reading the measurement with the eyes also the Alignment of the laboratory or work table is such that actually a measurement on the measuring section, which is generally a simple one Scale is can be made. A magnet could indeed be brought up to the device by hand and so with the hollow glass body align its magnetically releasable body in a desired manner, but this is associated with inaccuracies and uncertainties, if For example, the magnet brought in from the outside is too high or too low to be led. It is therefore more advantageous in the manner shown on To arrange the scope of the container at least one electromagnet, which is then also switched on in a well-defined manner and with electricity

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can be applied and switched off again, thereby avoiding by jerking a uniform movement of the hollow glass body in the liquid in the container can be achieved. In preferred Further development is provided that two diametrically opposite Electromagnets are provided. This creates a divergent magnetic field avoided that the hollow glass body with its magnetizable body located in it under the generated by the electromagnet Attraction or repulsion force could move radially in the container, so that the hollow glass body abuts the inner wall of the container and thereby the measurement to be made is impaired. As further training it can be provided that the coils contain iron cores.

It does not make sense that the alignment coils explained for the magnetizable Body in the glass tube before the glass tube is inserted are switched on in the container. It is therefore provided according to a preferred development that the coils are dependent from immersing the glass tube by means of an electronic unit Electricity can be applied.

In conventional hydrometers, there is the disadvantage that this at Insertion into the liquid to be determined too quickly and therefore initially immerse too far into the liquid via their equilibrium swimming state and carry out a damped oscillation process until they reach their stable swimming state. In this case, the outer circumference of the hollow glass body is then in one area wetted, which is in the equilibrium state above the liquid surface. This wetting can also affect the measurement result be affected. Basically, with the device already explained , but in particular in a device in which a weight arranged in the lower region of the hollow glass body is made of magnetizable Material consists, therefore provided in a preferred further development,

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that a plurality of radially aligned electromagnets is arranged symmetrically around the container and / or that at least one electrocoil is arranged coaxially around the container. Due to the coaxially arranged electrical or magnetic coil is reached when this coil is energized when the hollow glass body is introduced into the liquid, that the hollow glass body is initially held in a floating position which is higher than its stable swimming state, which is caused by the Archimedean principle is determined. The prerequisite is of course that the coil is in a suitable position relative to the liquid surface Way is arranged, but what the expert can easily find out for himself after the above. So the coil is not supposed to are arranged far below the liquid surface and, in particular, their distance from the liquid surface should not be greater than the maximum immersion depth of the floating hollow glass body in the Type of liquid to be tested. The flow of current through the coil can then be continuous after the glass body has been introduced into the container be reduced, the hollow glass body then slowly sinks to its floating state, immersing too deeply with it subsequent dampened vibrations and a wetting in not This avoids the desired areas. Better wetting can therefore be achieved through this configuration.

As I said, the same can be done with several symmetrically around the container arranged electromagnets can be achieved, these are aligned radially. In this case, of course, this must be switched on when switching on Electromagnets their iron-attracting part inside to the container be executed. With such an arrangement of electromagnets can but - regardless of their polarity, only either the polarity of all these electromagnets relative to the central axis of the container

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executed is the same - achieved that the hollow glass body in the center of the container is centered, touching the side walls of the container with inaccuracies caused by this is additionally prevented.

To be able to switch off the coils continuously, in In a preferred embodiment, for example, a potentiometer can be provided. Well, it doesn't make very good sense before even one Measurement carried out and for this purpose the hollow glass body in the container is immersed to keep the coils energized. It is therefore provided in a further preferred embodiment that the coils by means of an electronic unit immediately after immersion of the hollow glass body can be switched to their maximum strength. It It is important that the coils have their maximum value as soon as the hollow glass body begins to be immersed in the liquid, so that they hold the hollow glass body in suspension with maximum force and then you can then slowly lower it by slowly turning down the current.

While the above features essentially the accuracy of a device of the generic type and according to the invention increase the measurement to be carried out, taking the reading as a matter of principle can still be done visually, as far as a conventional scale is provided as a measuring section, is provided according to an extremely preferred embodiment, that a radiation source and a radiation receiver are arranged next to the container, the radiation receiver in which, from the radiation source to the measuring section and through this certain light path of a light beam lies, the radiation source in particular a light source and then preferably a laser and the radiation receiver is a light receiver, for example in the form

42,

a photodiode or a series of photodiodes. It goes without saying that, if necessary, suitable imaging optics can be provided. In principle, if the measuring section in the hollow glass body is a conventional scale, it can be projected Scale on a screen or the like - can be made - even after enlargement. This configuration according to the invention is the great advantage of a high accuracy and at the same time a large measuring range with a few manageable hydrometers achieved, while up to now a large number of measuring tubes for the most common density range was required. But to an automatic reading of the measurement result and to ensure further processing and registration is provided according to a first further preferred embodiment that a binary coded measuring section is present, which is preferably designed in that the measuring section consists of a plurality of in its direction of extension arranged, different rows of binary point elements consists. This enables discrete reading, with an error due to soiling of the glass vessel or the like the digital coding of the respective sinking depth of the hollow glass body is practically impossible.

An analog, continuous reading is possible because the Measurement section is designed analogously and continuously lets through less or more light in its direction of extension or else reflected. So can in a concrete constructive embodiment of the above analogous principle that the measuring section is an impermeable one that continuously widens over its length Has triangle, with either the triangle being blackened and has an adjacent see-through area or else that the triangle is mirrored. However, it can also be provided that the measuring section consists of a core with a changing direction in the direction of extension There is a permeability for the radiation of the radiation source, whereby again either the different permeability

may be due to a gray wedge arranged in the measuring section or a body located in the measuring section along "the measuring section different absorption capacity, so a different one has optical density. Automatic registration of the measurement result is made possible by the aforementioned configurations. This can then be used further in a variety of ways and is advantageously first processed via an electronic unit and then displayed either digitally or analogue or in a printer printed out. There are therefore advantageous in the inventive Device digital or analog displays and / or printer available.

The measurement of the density of a liquid or the concentrations of the Components of a liquid mixture is temperature dependent because the densities of the liquids change with the temperature and, in particular, change differently in the case of several liquids. Conventionally, one must therefore ensure that a fixed stable temperature, which is usually 20 C and should be referred to as the standard temperature, is maintained. To do this too To ensure the device according to the invention, it is provided in a preferred embodiment that first a temperature sensor in the container is arranged. In a further embodiment it is then provided that with the temperature sensor, a heating device and / or a cooling device with a cooling unit and cooling coils are arranged in the container are. The heating device and the cooling unit are then from the temperature sensor controllable so that the desired temperature, ie a standard temperature, can be maintained. In a special design the heating device and the temperature sensor can be as one part, namely be designed in the form of a PTC heating element, since s stabilizes itself at a given temperature and, in particular, approaches the temperature carefully. Includes such a heater a so-called PTC heating element, i.e. a heating element with positive

Temperature coefficient and generally consists of bear titanate or the like.- The preferred embodiment according to the invention with Temperature sensor either with the aforementioned heating and cooling devices or without this, it can also be developed in a preferred manner that the received from the radiation receiver Measurement signal taking into account the current temperature measured by the temperature sensor by means of an electronic Unit can be converted or standardized to a standard temperature. In this embodiment there is a heating or cooling device per se not necessary, as the resulting density or concentration value is automatically generated by the electronic unit relative to the temperature sensor measured temperature and then corrected as to a standard temperature reduced value is output. However, this device can also be advantageous together with the heating and / or cooling device be because this device initially a rough temperature setting of the liquid is achieved and then the remaining low Differences are still exactly balanced by the electronic unit can be.

Further advantages and features of the invention emerge from the claims and from the following description, in the preferred one Embodiments of the device according to the invention are explained in detail with reference to the drawing. Included shows:

Figure 1 shows a first embodiment of the fiction

according to the device for measuring the density of liquids in a schematic representation;

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Figure 2 is a view in the direction of the arrow il

Figure 1 on a measuring section; and

Figure 3 is a partial view of another preferred one

Embodiment of the device according to the invention in a view along the Section Ill-Ill derRgur 1.

The device 1 according to the invention for measuring the density of liquids and thus also for determining the concentration of Liquids, such as the alcohol content of an alcoholic one A beverage, such as wine, has a container 3 that holds the liquid 2. The device according to the invention also includes one in its lower part weighed down, glass tubes 4 closed on all sides, aiso a So-called hydrometer, which floats in the liquid 2 and dips deeper into it, the lower the density of the liquid. The weighing weight 6 located in the lower part of the glass tube 4 consists preferably of a magnetizable material, wis iron and is largely isotropically distributed in the lower part of the glass tubes 4. in the the upper part of the glass tubes 4 is a measuring section 7, which at conventional hydrometers is designed as a measuring scale in the illustrated embodiment according to the invention is designed in a manner described below. Furthermore, in the glass tube 4 in a plane perpendicular to the axis of the device and the glass tube 4 indicated by the arrow A-A, a magnetizable directed core 8 provided. The hydrometer or the glass tube 4 can in its lower Part of a meter scale, as is known per se, there the instantaneous density of a liquid depends on its temperature and therefore either a standard temperature can be assumed or it is based on such is to be converted. In the illustrated invention

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Embodiment of a device for determining the density of a liquid, no thermometer is required in the glass tube 4, since for this purpose other devices described below are made.

To the container 3 is in an area below a predetermined Liquid level 9 in the embodiment of the device according to the invention shown in Figure 1, a coil 11 is provided, which is connected to a current source 12 and whose current can be regulated by means of a potentiometer 13. Furthermore are on two opposite Sides of the container 3 inside perpendicular to the A axis lying level two magnet coils 14 are arranged, which are aligned with one another. The magnet coils 14 can each have an iron core exhibit. The magnetic coils 14 are connected to current sources 16 and can be switched on by means of switches 17. Here are preferred either the switches 17 can be operated together or the coils 14 are connected to a common power source 16, but care must be taken that their polarity is the same, i.e. that a north pole of one coil is a south pole of the other coil opposed, the coils 14 so with different polarities to the container 3 and thus to the glass tubes 4 and also to the magnetizable Core 8 are directed.

In one of the liquid mark or the liquid level 9 corresponding The plane is on the one hand a radiation source 18, such as a light source and in particular a laser, and on the other hand a radiation receiver 19, like a detector or a detector matrix arranged in such a way that light from the radiation source 18 after reflection in the Area of the measuring section 7 or - as in the present embodiment-

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example - after passing through the measuring section 7 in the radiation receiver 19 falls. The light source and / or detector can be moved in the vertical direction. Between the radiation source 18 on the one hand and measuring section 7 on the other hand and measuring section 7 on the one hand and radiation receiver 19 on the other hand can also have optical imaging elements be provided, which image the beam emitted by the radiation source 18 in a suitable manner, for example parallelize, in a preferred direction perpendicular to the beam direction imprint od. The like. These optical imaging elements are the better Overview has been omitted. Due to the capillary effect of the liquid to be determined, there are, so to speak, two reading points, once in the plane of the liquid surface and once the upper tear-off point of the glass tube due to surface tension rising liquid, which is largely tangential to the glass tube.

The measuring section 7 has in the illustrated embodiment from the figure 2 apparent configuration. In the direction of the axis A-A, the measuring section 7 is blackened continuously wider, so that a narrow one which is essentially stretched in the direction of the axis A blackened triangle 21 is created. No light passes through the blackened part of the measuring section 7, but only next to the one next to it remained, also along the axis A continuously changing free part 22. This achieves that of the radiation source 18 a different amount of light falls on the radiation receiver 19 depending on the immersion depth of the glass body 4.

Instead of a continuous measuring section, as shown in the Embodiment is provided, a digital measuring scale can be provided, for example, in the direction of the A axis has changing binary numbers, which are arranged in a row perpendicular to the axis A and are of such a detector

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- -: - *; :. . . -; .. .... series are received. In the simplest case, a conventional measuring scale with predetermined values can be provided, which is only projected onto a screen, so that no electrical processing arrangement is required.

Another continuous measuring section can be designed in such a way that the transmissivity of the upper part of the glass tubes 4 is along the axis A-A changes continuously, in which either in the light beam a gray wedge that continuously changes its thickness in the direction of the light beam is provided, or a body with over the height or is arranged in the direction of the axis A continuously changing absorption coefficient in the glass tube 4.

The signal captured by the radiation receiver 19 can be processed in an electronic unit 23, such as digital-analog converted, amplified and the like, are and is displayed via analog display instruments 24 or digital displays 26 or by means of a printer 27 is printed out. Of course, other storage options for the measurement results are also conceivable.

To measure the temperature of the liquid 2, a temperature sensor 28 is arranged in the interior of the container 3. The temperature sensor 28 controls a heater 29 via the electronic unit 23 so that the desired temperature for the liquid 2 in the container 3 is maintained. A cooling unit 31, for example an absorption heat pump, is also provided, by means of which the temperature of the liquid 2 can be reduced via cooling coils 32. The cooling unit 31 is in turn controlled by the temperature sensor 28 via the electronics unit 23. In a simple embodiment, the temperature sensor can also be designed together with the heating element 29 as a PTC element that stabilizes itself. Stabilization at a temperature of 20 ^° C. is then preferred.

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The temperature sensor 28 is also connected via the electronic unit to an analog display 33, a digital display 34 or the printer 27, so that the temperature is also displayed or printed out. In addition, the electronic unit 23 can contain a computer which, at any temperature of the liquid, converts the measurement result then obtained from the radiation receiver 19 to a standard temperature, for example 20 C, depending on the current temperature 28 measured with the temperature sensor. In ι
directions are omitted.

20 C converted. In this case, heaters or cooling units can

Finally, the electronics unit 23 can use the potentiometer 13 for control the magnetic coil 11, for example as a function of the complete interruption of the radiation source 18 emitted by the radiation Radiation through the weight 6. A control line 36 is provided for this purpose. In the same way, the electronics unit after the coil 11 has been switched off again, the coils 14 are switched on via the switch 17. The necessary Expensive lines are not shown for the sake of clarity. Further influencing parameters can also be compensated for by the electronic unit 23.

The device according to the invention works as follows:

To measure the density of the liquid 2 or the concentrations of its components, this is first in the container 3 up to Liquid mark 9 filled. The glass tube 4 is then sunk into the liquid. When interrupting the from the radiation source 18 to the radiation receiver 19 emitted radiation S is immediately via the electronics unit 23, the potentiometer the solenoid 11 has its maximum current applied to it. Through this the glass tube 4 is held in suspension so that the magnetizable Weight 6 is held approximately axially in the center of the coil 11, wherein this position above that determined by the Archimedean principle

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Position of the glass tube 4 in the liquid 2 lies. The current flow is then slowly and continuously via the potentiometer 13 in the coil 11 and thus the magnetic field generated by the coil 11 is reduced to zero. Some residual magnetization can if necessary. by applying a countercurrent to the coil 11 (not shown) are compensated. This procedure ensures that the glass tube 4 is carefully and slowly up to its through the Archimedes' principle lowers a certain sinking value into the liquid. It is avoided that by immersing too deeply what occur when the glass tube 4 is dropped into the liquid 2 could, a wetting takes place above the value of the measuring section 7 determined by the Archimedes' principle, whereby the measuring result could be affected. After the Coil 11 is then either manually or by the electronics unit 23 controlled, the switch 17 is closed and thus a directed magnetic field between the magnets 14 is exerted. This will make the magnetizable core 8 aligned such that the measuring section 7 in suitably to the radiation source 18 and the radiation receiver 19 stands. After aligning the core 8 and thus the glass tube 4 and the measuring section 7, the value given by the measuring section 7 is from Radiation receiver 19 is detected and via the electronics unit 23 displayed on the displays 24, 26 or printed out on the printer 27. Here, as already mentioned, normalization with regard to the temperature measured by the sensor 28 can be carried out by the electronic unit take place.

Regardless of whether such a temperature normalization takes place, in everyone However, if such a temperature normalization does not take place, the temperature sensor 28 and the electronic unit 23 as well as the Heating elements 29 and the cooling element 31, 32 a constant temperature

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the liquid 2 maintained.

In principle, there can be a risk that with a non-centric Immersing the glass tubes 4 these on the outer wall of the container and this can result in a falsification of the measurement result. To prevent such falsification, an embodiment according to FIG. 3 is provided. In this configuration are symmetrical arranged radially around the container 3 electromagnets 41, each may have an iron core and are connected to the power source 12 in such a way that they all face the center of the container 3 are aligned with the same polarity, this preferably being the magnetically attractive pole. This arrangement of the electromagnet 41 can initially in the same way as in the embodiment of Figure 1, the glass tubes 4 in a floating caused by the magnetic field This position is held and thus the glass tubes 4 are prevented from immersing too deeply in the liquid 2. The control of the current flow by means of the magnetic coils 41 takes place in the same way as in FIG. 1. Furthermore, however, the glass tube 4 becomes magnetizable by means of it Weight 6 centered around the axis A or held in the container 3, so that moving to the wall of the container 3 and bumping into it the same with the disadvantageous consequences mentioned above is prevented.

It can also be a combination of the coil 11 with the electromagnet 41 can be provided, whereby these can then also be aligned with the opposite polarity, since the magnetically induced levitation state the glass tube 4 is then ensured by the coil 11.

The device according to the invention provides a largely automated possibility of measuring the density of a liquid or the Concentrations of the liquid components using the Archimedes' principle achieved and thus a measurement by means of hydrometers significantly improved.

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The features of the invention disclosed in the above description, in the drawing and in the claims can both individually as well as in any combination for the realization be essential to the invention in its various embodiments.

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Bezugszeichenl iste 6372/82 Le

1
2
3
4th contraption
liquid
container
Glass tube 6th
7th
6th
9 weight
Measuring section
core
Liquids brand 11th
12th
13th
14th Kitchen sink
Power source
Potentiometer
Solenoid 16
17th
18th
19th Power source
counter
Radiation source
Radiation receiver 22nd
23
24 Free part
Electronics unit
Display instruments 26th
27
28
29 Digital display
printer
I feel the temperature
heater 31
32
33
34 Cooling unit
Cooling coil
Analog display
Digital display 36 Control line 41 Electromagnet

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Claims (31)

NACHOEFcE ₁ CV-J. . .- -.-..-. 3210719 DR. ING. HANS LICHTI "- 'DITL." ΓΝ G? "H ElTsI E K ' LiC HTI DIPL.-PHYS. DR. ÜOST LEMPERT PATENTANWÄLTE D-75OO KARLSRUHE 4I (CRÖTZ1NCEN) DURLAC H ER STR. 31 <H OC H HOUSE) TELEPHONE (0721) 4Ö5I! P 32 10 719.6 6372/82 Le Dr. Bernd Alber ₁₀ . August 1932 PATENT CLAIMS Device for measuring the density of liquids, in particular the concentration of the proportions of a liquid mixture with a stretched hollow glass body weighted in its lower part, a measuring section is provided in the direction of its extension and with one the liquid to be examined receiving container, characterized in that in the hollow glass body (4) an elongated, magnetizable body (8) with a perpendicular to the axis of the hollow body (4) Extension component is arranged and that at least one electromagnet (14) is arranged on the circumference of the container (3) is. 2. Apparatus according to claim 1, characterized in that two diametrically opposed electromagnets are provided. COPY must REALLY 3. Device according to claim 1 or 2, characterized in that that the coils contain iron cores. 4. Device according to one of claims 1 to 3, characterized in that that the coils depending on the immersion of the glass tube (4) by means of an electronic unit (23) with Electricity can be applied. 5. Device according to one of the preceding claims, characterized in that the glass body (4) contained in the hollow magnetizable body (8) are surrounded by electrical conductor loops. 6. 'Device according to one of claims 1 to 5, wherein in particular one in the lower area of the hollow glass body (4) Weight (6) consists of magnetizable material, characterized in that symmetrically around the container (3) a A plurality of radially aligned electromagnets (41) are arranged is. 7. Device according to one of the preceding claims, wherein in particular a in the lower region of the hollow glass body (4) arranged weight (6) consists of magnetizable material, characterized in that coaxially around the container (3) at least one electrical coil is arranged. 8. Apparatus according to claim 6 or 7, characterized in that the electrical coils (41) or the coaxial electrical coil (11) can be continuously supplied with current. COPY 9- Device according to claim 8, characterized in that the coils (11, 41) by means of a potentiometer (13) can be continuously acted upon. 10. Device according to one of claims 6 to 9, characterized in that that the coils (11, 41) by means of an electronic unit (23) directly after immersing the hollow glass body (4) can be switched on to their maximum strength. 11. Device for measuring the density of liquids, in particular the concentration of the proportions of a liquid mixture with an elongated hollow glass body weighted down in its lower part, A measuring section is provided in the direction of its extension is and with a container receiving the liquid to be examined, in particular according to one of the preceding Claims, characterized in that in addition to the container (3) a radiation source (18) and a radiation receiver (19) are arranged, the radiation receiver (19) in dam, from the radiation source (18) to the measuring section (7) and through this certain light path of a light beam (S) lies. 12. The device according to claim 11, characterized in that the radiation source (18) a light source and the radiation receiver (19) is a light receiver. 13. Apparatus according to claim 11 or 12, characterized in that that the radiation jellyfish (18) is a laser. 14. Device according to one of claims 11 to 13, characterized in that that the radiation receiver (19) consists of a perpendicular to the extension direction (A) of the glass tube (4) or the Container (3) arranged detector row consists. -ΌΡΥ REQUIRED 15 »Device according to one of claims 11 to 14, characterized in that the measuring section consists of a conventional Scale exists. 16. Device according to one of claims 11 to 14, in particular in connection with claim 14, characterized in that the measuring section from a multiplicity of different series of binary point elements arranged in its direction of extension (A) consists. 17. Device according to one of claims 11 to 14, characterized in that the measuring section (7) is one over their Impermeable triangle that widens continuously towards its length having. 18. Device according to one of claims 11 to 14, characterized characterized in that the triangle (7) is blackened and has an adjacent transparent area. 19. The device according to claim 17, characterized in that the triangle is mirrored. 20. Device according to one of claims 11 to 14, characterized characterized in that the measuring section consists of a core with a permeability that changes in the direction of extension (A) for the radiation from the radiation source (19). 21. Apparatus according to claim 20, characterized in that the different transmittance through one in the measuring section (7) arranged gray wedge is conditional. COPY FOLLOW-UPJ ■ '" · ^: - 22. The device according to claim 20, characterized in that a body located in the measuring section (7) along the Measuring section (A) has different absorption capacities. 23. Device according to one of claims 11 to 22, characterized characterized in that the radiation source (19) received signal can be processed via an electronic unit (23) is. 24. Device according to one of claims 11 to 23, characterized in that that the measurement signal received by the radiation receiver (19) can be displayed via an analog display (24). 25. Device according to one of claims 11 to 23, characterized • marked that the radiation receiver (19) received measurement signal can be displayed on a digital display (25). 26. Device according to one of claims 11 to 25, characterized in that that the signal received by the radiation receiver (19) can be printed out on a printer (27). 27. Device for measuring the density of liquids, in particular the concentration of the proportions of a liquid mixture, with an elongated hollow glass body weighted down in its lower part, In the direction of extension of which a measuring section is provided and with a liquid to be investigated Container, in particular according to one of the preceding claims, characterized in that a Temperature sensor (28) is arranged. COPY »JACHGEICHT 1 28. The device according to claim 27, characterized in that the measurement signal received from the radiation receiver (19) taking into account the current temperature measured by the temperature sensor (28) by means of an electronic Unit (23) can be converted to a standard temperature or can be standardized. 29. The device according to claim 27 or 28, characterized in that that a heating device (29) is provided and coupled to the temperature sensor (28). 30. Device according to one of claims 27 to 29, characterized. shows that the temperature sensor (28) and heating device (29) are designed together as a PTC heating device. 31. Device according to one of claims 27 to 30, characterized in that that a cooling unit (31) with cooling coils (32) is provided in the container (3), the cooling unit of the temperature sensor (28) can be controlled. COPY