DE3337501A1 - OPTICAL MEASURING TRANSMITTER - Google Patents

Description

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Optically he measurable variable converter

Besch friction

The invention relates generally to a transducer, in particular an improved Mc-iß size converter, whose Linearity is very good over an extremely wide dynamic range.

Such (measured variables) converters are usually used as an interface to a signal in a first To convert the reference system into a signal in a second reference system and thereby monitor the first signal or to measure or to use this signal for the control of a process or a variable.

Measuring transducers are used on a large scale, which respond to physical parameters, such as pressure, temperature, position, speed, Acceleration, etc. The output signal of many transducers is an electrical quantity, as facilities for Measurement and display of electrical parameters very much have reached a high level of development. The ability to move information linearly from a frame of reference to a Transferring another frame of reference is a very important property in development of all measuring transducers is aimed at.

There are transducers that are applied in relation to the Information and the reactions given, i.e. the response behavior, are very linear; in general Such transducers have this extreme linearity only over a small dynamic range. However, the broadest possible dynamic range is

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a critical variable in the effective use of a general, all-purpose transducer. In the usual requirements for the selection ⁵ or the development of a transducer for a specific purpose, two aspects are distinguished: First, linearity between the input signal to the transducer and the Desired output signal from the transducer. As a second aspect, the ¹ ^ width of the dynamic range, which is assigned to the input signal and the output values, is taken into account over the entire working range of the transducer.

The lower end of the dynamic range is defined by the! 5 smallest input signal to which the transducer is responding still responds linearly. This property is also known as "sensitivity"; in general is it is advantageous if a transducer is as sensitive as possible, i. that is, that the transducer to a The physical variable of interest should still react even if its value is as small as possible. The upper end of the dynamic range is defined by the largest input signal that the transducer can respond to responds linearly; this value should also be as large as possible.

Another essential property of the transducer is seen in its frequency behavior; this frequency response defines the relative amplitude of the output signal of the transducer as a function of oscillating input signals with different frequencies. Many physical variables that are to be measured or monitored are oscillating or dynamic Character; it is important that the transducer responds to the specific frequencies used in the or dynamic phenomena to be monitored are present.

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It is also essential that the transducer does not respond to certain other frequencies that the Should not affect measurements. One of the properties of a transducer that is worth striving for is that its frequency behavior can be adapted to different measurement situations.

In general, the transducers currently available depend to a large extent on the associated ones

Devices. This dependence causes problems in f- accurate transfer of information from the first

Reference system to the second reference system. These difficulties in accurately conveying information can vary in the resistance of the connecting cables, the weight of the transducer itself, the mechanical Wear associated with the transducer and the alignment of the device in a particular direction demonstrate. Problems of this type are extremely difficult to diagnose and eliminate. That's why many have the conventional embodiments of transducers have various disadvantages.

There is therefore a need for a new and unique [25 transducers, which can be adapted to many different measurement conditions and at the same time shows superior linearity between the input signal to the transducer and its output signal; this linearity should be maintained over an extremely wide dynamic range; In addition, this transducer should have a relatively simple structure and therefore be inexpensive to manufacture; Finally, it should be possible to adapt the frequency behavior of this transducer to different measurement situations without problems.

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Knowing the need for an improved transducer for the transmission of information from a first system to a second system, it is therefore a general feature of the present invention to provide a to create a new transducer that reduces or largely reduces the problems discussed above, specifically, the problems associated with non-linearity and narrow dynamic range.

It is therefore an object of the present invention to provide a new transducer with extremely high sensitivity, to create a very wide dynamic range and very high linearity.

Furthermore, a new transducer is to be proposed that is less sensitive to electrical Interference is. This should apply in particular when optical fiber elements are used.

It is another object of the present invention to provide a new transducer which has a broad Has a range of frequency characteristics and can be tuned to different resonance frequencies.

Furthermore, a new transducer is to be proposed which is not preloaded in a specific direction by alignment.
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And finally, a transducer is to be created in which there is no coupling between the input signal and the output signal emerges more and which produces a low impedance output signal. 35

This is according to the invention by the in the characterizing part

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of claim 1 specified features achieved.

Appropriate embodiments are in the unclaims compiled.

According to the present invention, there is thus a new transducer that has a linear response over a wide dynamic range. The transducer According to the present invention, an emitter for emitting rays is one of the emitter functionally associated detector for receiving the rays emitted by the emitter, 'where the rays or their extensions associated with the emitter and the detector at a common point of intersection converge, d. i.e., at a common focal point, and a reflective array that is at a distance is arranged from the common focal point, in order to the rays emitted by the emitter onto the detector to reflect; with a transducer for the determination a change in the distance between the location of the reflective arrangement and the location of the emitter and the detector based the appropriate determination on the difference in the amount of rays emitted by the Detector before or after the change in the distance between the reflector and the arrangement of emitter / detector be received.

The rays emitted by the emitter and received by the detector can be electromagnetic Radiation, sound waves, subatomic particles, heat rays and similar rays act. After a In a preferred embodiment, the emitter emits light rays. The transducer according to the present invention can work with incoherent light.

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According to a preferred embodiment, the converge rays emitted by the emitter and picked up by the detector by means of a focusing device in the common intersection. The focusing device according to the present invention should be an optical one Be a lens if the emitter is emitting light or some other form of optically refractive energy.

In the transducers according to the present invention the frequency response behavior can be changed by changing the mechanical properties (mass, rigidity, damping) adjusting a suspension system that supports the reflective surface; for this it is essential that the suspension system can respond elastically to an external force. Alternatively, the frequency response of the transducer according to the present invention by selectively changing the mechanical Properties of an elastic system can be set, which holds the combination of emitter and detector, when the emitter and detector are arranged to physically engage the external force.

The change in the location of the reflective surface will be used to measure or monitor the physical variable of interest by appropriately the physical variable is coupled with a change in the position of the surface. That way you can the converter or transducer is adapted to the determination of many different physical parameters such as pressure, speed, acceleration, altitude, etc.

The transducer according to the present invention can be easily adapted to components with optical fibers be to take energy to and from the reflective

To transfer surface law.

The invention is described below on the basis of exemplary embodiments explained in more detail with reference to the accompanying schematic drawings. Show it

Fig. 1 is a section, seen from the side, through a conventional, electrodynamic transducer for converting a speed into a corresponding electrical signal.

Figure 2 is a graph of frequency response of the transducer according to Figure 1 for an embodiment in which by using a external damping resistance, the frequency response is flattened.

Fig. 3 is a sectional view, seen from the side, of a preferred embodiment of a transducer according to the present invention for an optical geophone.

Fig. 4 is a diagram of a preferred embodiment of the transducer according to the present invention, combined with a representation of its frequency response 25

5 shows a diagram of a further, preferred embodiment of a transducer according to the present invention Invention, and

6 shows a perspective view of a further, preferred embodiment of a transducer according to FIG of the present invention with a device for changing the natural resonance frequency for an optical geophone.

To simplify the explanation of the improvements made with the transducer of the present invention

are achieved, is in Figures 1 and 2, a conventional, electrodynamic transducer for determining the Speed and its corresponding frequency response are shown. Figure 1 shows the basic structure of such conventional, electrodynamic transducer 10, which is enclosed in a housing 12. In the case 12 is a device for generating a magnetic field, namely an annular permanent magnet 14 and a pole piece 15. The annular permanent magnet 14 and the pole pieces 15 are fixedly attached to the housing 12. A coil 18 is suspended in the magnetic field generated by the magnet 14. The bobbin 16 is suspended by a spring 20 held. An electrical cable 22 is used to transmit the output information received from the coil 18 to pass on.

The electrodynamic transducer shown in FIG 10 is used to determine the relative vertical movement of the transducer. When the housing 12 and the magnet 14 tends to vibrate Coil 18 to remain stationary due to its inertia. The moving magnetic field generated by the magnet 14 creates a voltage across coil 18 that is proportional to the speed and displacement of the magnet 14 is. The frequency response that can be achieved by the electrodynamic transducer 10 can be through Using a resistor 2 5 can be changed with a different value.

Figure 2 shows the displacement / frequency characteristic of the electrodynamic transducer 10 according to Figure 1. The curve 24 represents the resonance natural frequency of the electrodynamic Measuring transducer 10 represents. From curve 24 it can be deduced that the response behavior of zero Hertz (Hz) up to the resonance frequency of the system (at approximate

wise 22 Hz) and then drops to the level of the response behavior for higher frequencies.

However, every transducer should have a flat frequency response. Therefore, as is generally required to attenuate the electrical signal that a transducer, such as the electrodynamic converter 10 is assigned. The signal can be changed by changing of the resistance value of the resistor 25 (see Figure 1) can be attenuated. The curves 26, 28 and 30 for different Frequency responses represent the effect of three different resistance values of the damping resistance, achieved by changing the resistor 25, on the frequency characteristic of the electromagnetic transducer 10. Curves 26, 28 and 30 simultaneously also show the undesirable side effects discussed above. These undesirable side effects are based on the attenuation of the frequency response, which was necessary to maintain a flat frequency response. The undesirable properties found in curves 26, 28 and 30, in particular, are the loss of sensitivity, the shift in the tip of the Frequency response to higher frequencies and finally the change in the phase characteristic.

In addition, there are other factors that have to be taken into account when using it of transducers which are similar to the electrodynamic converter 10 lead to problems. In particular can increase the sensitivity of the electrodynamic The transducer 10 can be improved by increasing the number of turns of the wire in the coil 18. The increased However, the amount of wire increases the weight of the electrodynamic transducer 10. Such an increase in weight must be avoided, however, if movements are to be measured with such a device. aside from that

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occur in devices that use the electrodynamic transducer 10, have problems with mechanical wear on the moving parts; and finally must ° the electrodynamic transducer 10 very precisely in Be aligned with respect to the vertical, the particular alignment selected from the design of the coil suspension depends. If this exact alignment is not given, the coil would be outside the short Gaps lie and work in which the magnetic field is approximately constant, which creates a strong distortion of the output signal of the transducer would result.

The transducer according to the present invention does not have the disadvantages mentioned above, since the detection of the respective measured variable takes place without any direct contact; the input signal on the one hand and the output signal on the other are therefore completely isolated from one another, so that the frequency response of the transducer is not damped externally must become.

Figure 3 shows a cross-sectional view, seen from the side, through an embodiment of the transducer 32 according to the present invention for an optical geophone. This transducer 32 is held by a housing 34. The case 34 serves to establish the connection to the other components of the transducer 32 and these components to keep. A reflective surface 36 and a Emitter / detector modules 38 are attached to the interior of housing 34. The emitter / detector module 38 emits rays which hit the reflective surface 36. The reflective surface 36 redirects these rays, so that it can be received by the emitter / detector module 38. The emitter / detector module 38 is through a Cable 40 fed.

In the embodiment of Figure 3, either the reflective surface 36 or the emitter / detector module 38 elastic with the main part x 34, i.e. i.e., the housing. When the transducer 32 is a component of motion in the longitudinal direction, depending on which part is elastically connected to the housing 3 4 is, either the reflective surface 36 or the emitter / detector module 38 due to their inertia in their Stay in position. This changes the distance between the reflected j generating surface 36 and the emitter / detector module 38 when the transducer 32 is displaced in the longitudinal direction. This change the distance between the reflective Surface 36 and the emitter / detector module 38 is indicated by a change in the amount of energy received from the Emitter / detector module 38 is received before and during movement.

In the embodiment of the transducer shown in Figure 3 the reflective surface 36 is resiliently connected to the housing 34, while the emitter / Detector module 38 is fixedly attached to housing 34.

In the embodiment of the present invention shown in FIG. 4, the reflective surface can 36 be maintained by appropriate means. For example, the reflective surface 36 can only be on two sides be stored, it can be gimbaled, held by a spring or supported by torsional forces be. The mechanical properties of the suspension determine the frequency response of the transducer. Practically any desired frequency response can be achieved by suitable selection of the mechanical parameters of the suspension. Any other type of vibrating, reflective surface can also be used, for example Magnetic fields. Each reflective surface 36 is

acceptable as long as this surface 36 during a movement of the housing 34 due to its inertia or by other means can remain stationary.

As an alternative to this, the emitter / detector module 38 can also be elastically attached to the housing 34; in this In the case, a rigid structure is used as the reflective surface 36.

Figure 4 shows schematically a preferred embodiment a transducer according to the present invention. The elements of the embodiment of FIG. 4 are based on the Use of an optical transducer directed; in principle, however, other operating principles are also possible.

The transducer according to FIG. 4 has a reflective Surface 36 on which the light rays emitted by the light source 32 strike. The light source 32 generates Rays passing through focusing device 44 and converging at a focal point 60; this focal point is located is on the opposite side of the reflective surface as viewed from the light source 42 The rays striking the reflective surface 36 are directed back to the photodetector 48. The focusing device 46 ensures that the photo detector 48 Receives rays with the focal point 60. So both the generated and received beams have the common focus 60.

The light source 42 can be visible, infrared, or ultraviolet light hand over. It is also possible to apply the basic principle of the present invention to other forms of energy to apply as light, taking the appropriate

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Form of energy only has to propagate linearly. This means that the source 42 any form of electromagnetic radiation, Sound waves, subatomic particles, heat or a similar form of energy can emit through the focusing device 44 is focused on the focal point 60. This energy can then be transferred to a suitable reflective surface 3 take 6 to reverse in direction and from the detector 48 after passing through another Focusing device 46 with the same focal point 60 to be received.

FIG. 4 also shows a graphic representation of the output signal of the transducer when the position changes the reflective surface 36. The curve 50 represents the output signal of the light detector 48, i. H., an electrical signal corresponding to the intensity of the incident light. The curve 50 has a rising Starting area 52, a sloping end area 54 and a tip 56. The lower, increasing starting range 52 and the upper, sloping end portion 55 have a substantially linear shape.

The main feature of the transducer according to the present The invention is seen in the fact that this transducer generates a linear output signal. at the point 60 is a common focal point in which both the source 42 and the detector 48 are imaged by the focusing devices 44 and 46, respectively. The common focal point 60 is near but at a distance from the reflective surface 36. When the reflective surface 36 is displaced from the common focus 60, the output will follow the Detector of either the upper side 54 or the lower side 52 of the curve 50 of the detector output signal. That means that the output signal of the transducer

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in a linear relationship with the location of the reflective Surface.

The following can be derived from FIG. 4: If the reflective surface 36 is in its rest position, then it is located them on line A in Fig. 4; i.e., its location coincides with point 32 on the upper side 54 of curve 50 of the Output signal of the detector together. With a movement of the reflective surface 36 shows the curve 50 of the Output signal of the detector indicates that this output signal and thus the response behavior of the transducer will be in a linear relationship with the movement of reflective surface 36 as long as the deflection is not the tip 56 or the top of the top 54 or the bottom of the bottom 52, respectively exceeds.

Due to the structure described, a small displacement of the reflective surface 36 causes an extreme large change in the output of the photodetector 48. When the focal point 60 is in the plane of the reflective Surface 36 is arranged along line A, the output signal of the detector would be particularly insensitive to it a displacement of the surface 36. Therefore, the focal point 60 should be selected so that the focal point in the corresponding area of curve 50 of the Aus · ^ output signal of the detector is; the correct selection of these Location is a critical parameter of this transducer. If this interpretation is made so that the range of motion of the reflective surface 36 along the linear, d. That is, rectilinear parts of the curve 50, there are various advantages, for example one very good linearity of the output signal in terms of the amplitude of the oscillation, a wide dynamic range and

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high sensitivity to external forces.

In the case of transducers where a large value is placed on the shielding against external electrical interference, an optical fiber cable can be used. figure shows in the form of a diagram of a preferred embodiment of a transducer according to the present invention, which makes use of the technology of fiber optics. An outer transducer chamber 34a may be remote from a Recording station 70 are arranged. The recording station 70 includes a light source 72, a photodetector 74, focusing devices 76 and 78, and a beam splitter 84. The outer transducer chamber 34a contains a reflective surface 36a and a focusing device 82. The recording station 70 and outer transducer chamber 34a can be connected via an optical fiber cable be connected. The transmitted and received light would be transmitted over the optical fiber cable 80.

The light is emitted from the light source 70 and focused by the focusing device 76 so that it is the optical fiber cable 80 happens. The optical fiber cable 80 brings the emitted light to the outer transducer chamber 34a, where it is refocused on reflective surface 36a by focusing device 82. That at the Light reflected from the reflective surface 36a then traverses its original path again through the Focusing device 82 and the optical fiber cable 80.

The beam splitter 84 then directs the beam through the focusing device 78 onto the photodetector 74. The Beam splitter 84 serves to separate the light traveling in both directions. By using the optical fiber cable 80 and a recording station 70, which is arranged at a distance from the outer transducer chamber 34a, is the transducer shown in FIG free from any induced electrical

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Disruptions.

6 shows a perspective view of an embodiment of the transducer similar to that described above and FIG in Fig. 4 embodiment shown is similar. In particular, the transducer of Fig. 6 shows a mechanism for changing the frequency response of an optical geophone. I.

This transducer is enclosed in a housing 34b. _i

_l Q in the housing 34b, an emitter / detector module 38b is shown, j This emitter / detector module 38b directs the light rays ^ generated on the reflecting surface 36 b. The reflective surface 36b has a fixed, that is to say stationary, first end 90 and an adjustable, second end 92. The second end 92 of the reflective surface 36b can be adjusted using a screw 94.

The emitter / detector module 38b directs the generated light beams against surface 36b. The resonance frequency of the transducer shown in Fig. 6 can be to each desired frequency value can be changed by adjusting the screw 94 accordingly; this screw 94 exercises a tension on the reflective surface 36b which can be increased or decreased as desired. Through this Any desired resonance frequency can be set by using the transducer according to the present invention voted in the appropriate manner.

Claims (26)

GRÜNECKER. KINKEELDEY. STOCKMAIR & PAR T NER :O' rWENTANWAUi: A GRUNtCK! H. in uo on η κινκκι.οι υ ι ·· *. "*> OH W STOCKMAIH. ι »ιι · ο» OR K SCHUMANN. c «n« · "' f H JAKOEl. i »» i. · «< OM G (ΛΚ2ΟΙ t). t> n C "> m W.MKI & TfcR.i «-. “M H. Hit OURS. t »v i ~ r. OH H MEiYt HI ¹ LATH. on .. «> GULF APPLIED TECHNOLOGIES, INC. 10665 Richmond Avenue, suite Houston, Texas 77042 United States 80OO MUNCt UN WJ P 18 329 Optical transducer Patent claims 25 Γΐ / transducer with linear response behavior and with a wide dynamic range, characterized by a) an emitter (42) for generating rays,
by b), a De- I functionally assigned to the emitter detector (48) for receiving the beams emitted by the emitter (42), the beams emitted by the emitter (42) and those emitted by the detector (48)
received rays form a multitude of geometric lines or their extensions, leading to one converge toward common intersection point, and by c) a reflective, at a distance from the common intersection point (60) arranged in the beam assembly (36) to the enclosed by the emitter (42) abgege- ■ j rays to the detector (48) to reflect, wherein the measurable variable converter detects a change in the distance between the location of the reflective arrangement (36) around the location of the emitter (42) and the detector (48) by utilizing the difference in the amount of rays emitted by the detector (48) before and after the change in the distance between the location of the reflective arrangement (36) and the location of the emitter (42) and the detector (48) are received, whereby the linearity of the output signal of the transducer (32) over a wide, dynamic range of Values of the displacement distance is improved. 2. Transmitter with linear response behavior and with a wide dynamic range according to claim 1, characterized in that the emitter (42) is light waves gives away. _ ₅ 3. measuring transducer with linear response and with a wide dynamic range, according to claim 1, characterized in that the emitter (42) emits electromagnetic rays. 4. Transmitter with linear response and with a broad dynamic range according to claim 1, characterized in that the emitter emits sound waves . 5. Transmitter with linear response behavior and with a wide dynamic range according to claim 1, characterized in that the emitter emits subatomic particles. 6. transducer with linear response and with a wide dynamic range according to claim 1, characterized in that the emitter gives off heat. 7. transducer with linear response and with a wide dynamic range according to a dbr claims 1 to 6, characterized in that the reflective Arrangement (36) between the emitter (42) and the common point of intersection of the beams or their extensions, emitted by the emitter (42) and the beams or their extensions provided from the Detector (43) are received. 8. transducer with linear response and with a wide dynamic range according to one of the claims 1 to 7, characterized in that the common point of intersection of the rays emitted by the emitter (42) and the rays received by the detector (48) are between the emitter (42) and the detector (48). 9. Optical transducer with linear response and with a wide dynamic range, characterized by a) a housing (34) through b) an emitter (42) assigned to the housing (34) for generating light beams c) a detector (48) which is functionally assigned to the housing (34a) and the emitter fixed relative position with respect to the emitter (42) for receiving the emitted by the emitter (42) Light beams, the light beams emitted by the emitter (42) and the light beams emitted by the detector (48) received light rays, several, geometric lines or their extensions form, which to one converge common point of intersection, and by d) one of the housing (34) assigned and at a distance from the common point of intersection of the light beams, reflective surface (36) which fall the light rays, wherein the transducer (34) a change in the distance between the location of the reflective surface (36) and the location of the emitter (42) and the detector (48) by using the difference in the amount of light that is detected by the detector (48) and after changing the distance between the location of the reflective surface (36) and the Location of the emitter (42) and the detector (48) is received, reducing the linearity of the output signal of the transducer (32) over a wide dynamic range of values of the changed Distance is improved. 10. Optical transducer with linear response according to claim 9, characterized in that the emitter (42) and the detector (48) resilient to the housing (34) for movement by an external force are coupled. 11. Optical transducer with linear response according to one of claims 9 or 10, characterized in that the reflective surface (36) is resiliently coupled to the housing (34) for performing a movement by an external force. 12. Optical transducer with linear response according to one of claims 9 to 11, characterized in that the reflective surface (36) is in between the emitter (42) and the common point of intersection (48) of the light rays or their extensions. 13. Measurement transducer according to one of claims 9 to 12, characterized in that the common point of intersection the light beams is arranged between the emitter (42) and the detector (48). 14. Optical transducer with linear response and with a wide, dynamic range, marked by a) a housing (34a) through b) an emitter (72) assigned to the housing (34a) for generating light beams c) a detector (48) which is functionally assigned to the housing (34) and the emitter fixed relative position in relation to the emitter (72) for receiving the from the emitter (72) emitted light rays through d) a focusing device which is functionally assigned to the emitter (72) and the detector (74) (76, 78, 80, 82) for the guidance of the emitter (72) and the detector (74) received light rays for shaping these light rays or their extensions in such a way that they converge towards a common point of intersection, and through e) one assigned to the housing (34a) and at a distance from the common point of intersection of the light beams arranged, reflective surface (36a), on which the light rays fall, the transducer a change in the distance between the location of the reflective surface (36a) and the location of the emitter (72) and the detector (74) by evaluating the difference in the amount of light detected by the detector (74) before and after the change in distance between the location of the reflective arrangement (36a) and the location of the emitter (72) and the detector (74) is received, whereby the linearity of the output signal of the transducer over a wide dynamic range the value of the changed distance is improved. 15. Optical transducer with linear response according to claim 14, characterized in that the emitter (72) and the detector (74) with the housing (34a) are coupled for the implementation of a movement under the action of an external force; ' 16. Optical transducer with linear response according to claim 14, characterized in that the emitter (72) and the detector (74) with the housing (34a) coupled to perform a movement by an external force, and that the frequency response is selective Changing the parameters of the coupling between the housing (34a) on the one hand and the combination of emitter (72) and Detector (74) on the other hand can be adjusted. 17. Optical transducer with linear response behavior according to one of claims 14 to 16, characterized in that that the reflective surface (36a) with the housing (34a) for performing movement under the action of an external force is coupled. 18. Optical transducer with linear response behavior according to one of claims 14 to 17, characterized in that that the reflective surface (36a) with the housing (34a) for performing movement under the action of an external force is coupled, and that the frequency response by selective change the parameters of the coupling between the reflective surface (36a) and the housing (34a) can be adjusted can. 19. Optical transducer with linear response behavior according to one of claims 14 to 18, characterized in that that the reflective surface (36a) between the emitter (72) and the common point of intersection of the rays of light or theirs. Extensions lies. 20. Optical transducer with linear response according to one of claims 14 to 20, characterized in that that the common point of intersection of the light rays between the emitter (72) and the reflective Surface (36a) lies. 21. Optical transducer with linear 'response according to one of claims 14 to 20, characterized in that that the common point of intersection of the emitter (72) emitted and received by the detector (74) Light rays the common focal point of the focusing device for the emitter (72) and for the Detector (74) is. 22. Optical transducer with linear response behavior according to one of claims 14 to 21, characterized in that that the emitter (72) emits incoherent light. 23. Optical transducer with linear response behavior according to one of claims 14 to 22, characterized in that that the emitter (72) emits infrared light. 24. Optical transducer with linear response behavior according to one of claims 14 to 22, characterized in that that the emitter (72) emits ultraviolet light. 25. Optical transducer with linear response hold according to one of claims 14 to 22, characterized in that that the emitter (72) emits visible light. 5 26. Optical transducer with linear response behavior according to one of claims 14 to 25, characterized through fiber optics (80) for the transmission of the light to and from the reflective surface (36a). 10