CH696893A5 - Search antenna polarization instrument for a material-detecting device. - Google Patents

Description

CH 696 893 A5

description

The invention relates to a search antenna polarization instrument for a material detection device.

In a contribution already received in 1934, Wüst and Wimmer report on novel vibrations in the environment of organic and inorganic substances as well as biological objects. The results were, however, relatively poorly reproducible and inaccurate.

So-called magnetometers are known for detecting iron. Furthermore, metal detectors or so-called metal detectors are available on the market. The metal detectors available on the market usually use coils, and these send out a signal in a certain direction and then measure the returning, reflected signal. However, the devices mentioned have the disadvantage that they are to be held directly on the object sought. With these devices, a location from a greater distance is therefore not possible. But even if the devices are held in the immediate vicinity next to or on top of the searched object, they do not indicate the desired object or the searched material.

The invention has for its object to provide a search antenna polarization instrument for a material detection device, which is more versatile and in particular able to find the sought material or object over a greater distance away.

This object is achieved according to the invention by a search antenna polarization instrument having the features of patent claim 1. Advantageous developments are the subject of the dependent claims.

With the help of a capacitor and the soft magnetic electrodes used in the process, the sought material can be scanned for its specific width and length ratios, so that the dimensions of the material can be determined. With the instrument according to the invention, it is possible to determine the position of the material sought over a greater distance.

The specified in claim 1 parts of the search antenna polarization instrument form a resonant circuit, wherein the resonant body forming the antenna is the inductance L of the resonant circuit. If the resonating body constituting the antenna is made of ferromagnetic material (such as dynamo plate, Mumetall®, permalloy, carbonyl iron or other soft magnetic materials), the aforementioned inductance L of the resonating body increases by the magnetic permeability number as material constant. This allows for the resonant circuit a small capacity for resonance tuning. This makes it easier to eliminate noise and preserve the resonant frequency.

According to one embodiment of the invention, the rotatable body forms the upper part of the search antenna polarization instrument and has the vertical orientation of the instrument on its upper side a spirit level, preferably in the form of a circular level. In particular, the vertical alignment of the search antenna polarization instrument can be established or checked.

According to another embodiment of the invention, the preferably two-pole resonant body, the insulating layer and the Mumetall® layer by means of these parts penetrating, central screw, preferably a hollow screw with inner tuning screw, attached to the printed circuit board. As a result, the aforementioned parts are securely held on the printed circuit board and attached directly to this, so that the inventive device can be constructed extremely compact.

Advantageously, the insulating layer is made of polycarbonate and formed the Mumetall® layer in the form of a magnetic lens. Polycarbonate is a good insulator with a comparatively low weight.

According to a preferred embodiment of the resonant body is a transmitting and receiving antenna, by means of, for example, for determining the distance a transit time measurement is feasible by the signal emitted by the resonator body, a pulse superimposed and the duration of the pulse, i. the time is measured until the pulse has returned to the resonator body returning from the found material. Thus, the resonant body in the sense of a double effect in a position to send out and receive electrical signals.

According to a particularly preferred embodiment of the invention, the resonant body is hair-shaped or tubular, rectangular, rectangular-arcuate, lenticular, part-circular, arcuate, formed with or without one or more indentations or a combination of the aforementioned forms and preferably has one Hole on. Thus, a large number of resonant bodies are available for practical applications, so that a suitable resonant body can be selected for each application.

According to one embodiment of the invention, the one or more indentations are shaped like a circle.

Advantageously, the search antenna polarization instrument preferably has a light emitting diode, a connection for a headphone or an electrical measuring device and / or a built-in speaker. This makes it particularly easy to display the detected signals, so therefore perceive visually or acoustically.

According to a particularly preferred embodiment of the invention, the signal received from the found material is polarized, wherein preferably the diameter of the resonator corresponds to the wavelength of the signal or its fraction and ji3, tx3 / 2 or tx3 / 4. Thus, the diameter of the resonator of the

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Wavelength of the signal received by the detected material. But it is also possible that the diameter of the resonator corresponds to even fractions of the wavelength of this signal. Thereafter, the diameter of the resonator depends on the sought or found material and can be easily determined on the basis of the aforementioned design rule.

Further embodiments of the subject invention are specified in the dependent claims.

Embodiments of the subject invention are explained below with reference to the drawing. Show it:

Fig. 1 is a schematic front view of a search antenna polarization instrument;

FIG. 2 shows a schematic side view of the instrument according to FIG. 1; FIG.

Fig. 3 is a schematic plan view of the instrument according to Fig. 1;

4 shows a schematic, partial vertical section through the upper part of the instrument;

Fig. 5-17 are schematic representations of a resonator of the instrument mainly in each case in a plan view;

FIG. 18 shows a resonance body in the form of a converging lens; FIG.

Fig. 19 is a schematic front view of a resonant body called a pinch;

FIG. 20 shows a section through the resonance body according to FIG. 19; FIG.

Fig. 21 is a schematic plan view of the resonant body called the pinch;

22 shows a schematic, partial vertical section through the upper part of the instrument according to another embodiment; and

FIG. 23 is a circuit diagram of a series resonant circuit used in the instrument. FIG.

In Figs. 1 to 3 different views of a material detector device 1 are shown schematically. In detail, the material detector device 1 is shown in a front view in FIG. 1, in a side view in FIG. 2 and in a plan view in FIG. 3.

The material detector device 1 has a search antenna polarization instrument 2. 1 has a rotatable body 3, which forms the upper part 4 of the search antenna polarization instrument, and a base body 5. The base body 5 forms the lower part of the search antenna polarization instrument 2, as shown in FIG is shown. The rotatable body 3 is seated on the base body 5. The rotatable body 3 and the base body 5 are concentric with each other and have a common longitudinal axis 6.

On its upper side 7, the rotatable body 3 has a spirit level 8, which is designed according to a particularly preferred embodiment in the form of a circular level. The bladder 9 is shown in a side view respectively in Figs. 1 and 2 and in a plan view in Fig. 3. The spirit level 8 is used in particular for vertical alignment of the instrument, in which the longitudinal axis 6 is perpendicular to a bottom not shown in detail.

The rotatable body 3 further has a pointed downward, i. to the base body 5 tapered marking 10, the lower tip of which ends at the lower edge 11 of the rotatable body 3. At the upper edge 12 of the base body 5 is located, so to speak, the tip of the marker 10 opposite, a graduated scale 13. In Fig. 1, the graduated scale 13 at the level of the longitudinal axis 6 is 0 degrees. For the left in Fig. 1 side, the graduated scale 13 has a division between 0 and +90 degrees, on the right in Fig. 1 side down from 0 degrees to -90 degrees. The left half in FIG. 1 can also be seen in the side view according to FIG. 2 of the material detector device 1. It is clear that the connecting line between the value +90 degrees on the graduated scale 13 and the longitudinal axis 6 with the connecting line between the value 0 degrees of the degree scale 13 and the longitudinal axis 6 encloses a right angle.

The base body 5 also has a in Fig. 2 only dash-dotted lines indicated printed circuit board 14 with several, also only dash-dotted lines indicated electronic elements 15. At its in Fig. 2 bottom end of the printed circuit board 14 has a plurality of dash-dotted lines indicated 16, which with a 9 volt battery 17 are in contact. The 9-volt battery 17 has a housing not shown in detail preferably made of nickel and is inserted from the outside into a recess 18 of the base body 5. As indicated in FIGS. 2 and 3, the outer end of the battery protrudes outwards beyond the jacket-shaped outer contour 19 of the base body 5.

On the outer contour 19 are also a light emitting diode 20 and a terminal 21, for example, for a headset not shown in detail or an electrical meter. Further, a speaker may be incorporated in the base body (not shown). LED 20 and connector 21 and optionally loudspeakers are connected to the PCB

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14 and are located on that side of the printed circuit board, which also has the aforementioned electronic elements 15. As illustrated in FIG. 3, the light-emitting diode 20 and the terminal 21 are located on the side of the base body 5 opposite the 9-volt battery 17.

The more detailed structure of the search antenna polarization instrument 2 is shown in a partial vertical section of Fig. 4.

The rotatable body 3 has an inner shoulder 22 for receiving a magnetic disk 23 which is, for example, a plastoferrite magnet. With the help of the magnetic disk 23 can be adjusted by turning the rotatable body 3, the polarization angle 24 and read off on the graduated scale 13.

The base body 5 of the search antenna polarizing instrument 2 has an antenna body forming an antenna 25, one side 26, in Fig. 4, this is the upper side, facing the magnetic disk 23 of the rotatable body 3 is arranged. Further, the base body has a to the opposite, other side 27 of the resonator 25 subsequent insulating layer 28, which is preferably made of polycarbonate. In addition, the base body 5 has a Mumetall® layer 29 which adjoins the insulating layer 28 and which is preferably in the form of a so-called magnetic lens. Rotationally symmetric magnetic fields, e.g. are generated by current-carrying coils act on charged particles, such as. As electrons or ions that remain in the vicinity of the field axis, focusing. In order to be able to build lens fields as strong as possible, the field is focused on a small space with the help of pole shoes by means of the magnetic lens. Such magnetic lenses are also called Polschuhlinsen. The Mumetall® layer 29 is a permalloy alloy of 76% nickel, 17% iron, 5% copper, 2% chromium and at most 0.1% carbon.

According to the invention, resonance body 26 and Mumetall® layer 29 form a capacitor 30, which is electrically connected to the printed circuit board 14 having electronic elements 15. The electronic elements 15 are omitted in Fig. 4 for the sake of simplicity. With the aid of the abovementioned components, it is possible to determine in more detail the frequency and / or amplitude of the signal received by the found or searched piece of material (this is denoted by reference numeral 46 in FIG. 3) and thereby the type and location and optionally also the size to determine the piece of material.

The preferably two-pole resonator body 25, the insulating layer 28 and the Mumetall® layer 29 are centrally penetrated by a screw 31 which is formed as a hollow screw, and secured by a nut 32 to an L-shaped bracket 33 which the Printed circuit board 14 receives and is electrically connected thereto. Also located between the bracket 33 and insulating layer 28 is a rivet sleeve 34. Between the screw 31 and the cylindrical inner wall of the rivet sleeve 34 is also a Teflon sleeve 35. In addition, extends between the nut 32 and the holder 33, a Teflon ring 36. As in Fig 4, the Teflon sleeve 35 extends at least partially through the insulating layer 28 and through the Teflon ring 36. In this respect, the Teflon ring could also form a kind of flange of the Teflon sleeve and be integrally formed with the latter. In addition, a so-called tuning screw 37 is screwed into the screw 31 from below, which serves to fine-tune the emitted and / or received signals.

According to the invention, the resonator body 25 is a transmitting and receiving antenna, by means of the distance determination, i. for determining the distance between the material-detecting device 1 and the material piece 46 schematically shown in Fig. 3, a transit time measurement is feasible by superimposing a pulse on the signal emitted by the resonator body 25 and measuring the transit time of the pulse, i. the time is measured until the pulse has returned to the resonator body returning from the found material.

Individual embodiments of the resonance body 25 are shown predominantly in a plan view in FIGS. 5 to 17. Preferably, the resonance body is made of pure nickel. It should be noted that, in particular in FIGS. 5 to 8, only the left-hand half mirrored on a longitudinal axis 47 of the resonance body 25 is shown in solid lines. The right, second half of these resonator body is shown by way of example only in FIGS. 5 and 8 by dashed lines. Finally, all the other embodiments of the resonator body except the resonant bodies shown in FIGS. 13, 16 and 17 as well as the resonator body shown in FIGS. 19 to 21 can be mirrored with a second half on the longitudinal axis.

In Fig. 5, the resonance body is like a resonant hair or L-shaped. Fig. 6 shows a tubular formation, while in Fig. 7, a rectangular resonator body 25 is shown. It will be understood that with respect to the shapes shown in Figs. 5 and 6, the term resonance disk for the sounding body is not to be construed strictly literally and to be construed so broadly that subsumed below are the forms shown in the figures. In Fig. 6, the resonant disc is shown in a side and front view, respectively. In this embodiment, the base surface 48 is a circular disc, and the tube 49 has a cylindrical cross-section.

In Fig. 8 is a rectangular-arc-shaped configuration of the resonator body 25 is shown. Lenticular embodiments are shown in Figs. 9 and 10, wherein the upper flattening 38 with the right boundary line 39 of the resonator 25 in Fig. 9 includes an angle 40 of about 45 ° and in Fig. 10 an angle 40 of about 30 °. In Figs. 11 to 13 of the resonator body 25 are formed approximately semicircular, wherein the of the two legs

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41 and 42 of each resonating body 25 included angle 43 in the case of Fig. 11 180 °, in the case of Fig. 12 is about 171 ° and in the case of Fig. 13 is about 189 °.

14 and 15, the resonating body 25 are arcuate, wherein in the embodiment shown in Fig. 14, a 90 ° arc 44 and in Fig. 15 two 90 ° bows 44 are provided.

Further, the resonator body may have one or more indentations 45. 16 and 17 are two mutually diagonally opposite notches 45 and in Fig. 17 four pairwise opposite notches 45 are provided. The resonator body preferably has a central bore 64. But it is also possible that the resonance body has only one notch 45 or is formed from a combination of the aforementioned or other forms. According to a particularly preferred embodiment, the notch or the plurality of indentations is shaped like a circle.

Further embodiments of the resonant body or the resonant disc are shown in FIGS. 18 to 21.

Fig. 18 shows a plan view of a resonance body 25 in the form of a so-called condenser lens. For the flattening angle α indicated in FIG. 18, the relation holds:

--1 a = 29.7177 °.

The resonator 25 shown in Figs. 19 to 21 is called Pinch. It is approximately like the resonance body shown in Fig. 12 including the right, mirrored half, not shown in Fig. 12, but much thicker than those formed.

19 is a schematic front view, in FIG. 20 a section through the resonance body according to FIG. 19 and in FIG. 21 a plan view of such a resonance body. As shown in Fig. 19, the resonator 25 has the diameter D and the thickness D / 2. Fig. 20 illustrates an insulator 50 and electrical conductors 51, 52, of which the latter forms the lateral surface 53 of the resonator. FIG. 21 illustrates that the resonance body 25, which is designed as a so-called pinch, has a notch 45.

It is also possible according to an embodiment, not shown, to form the resonator in the form of a cone or a pyramid. It is clear that the chosen term "resonant disc" is to be interpreted in such a way that it also includes such antenna forms. Such a cone can be formed, for example, by forming a tip cone above the resonance disk, for example according to FIGS. 11 to 13 and 16 and 17. It is clear that in this case the rotatable body 3 is designed such that such antenna shapes find space therein.

Assuming that in Fig. 5, the length of the resonator L and the radius r is and under the further assumption that in Figs. 11,12 and 13 r respectively the radius and U respectively the circumference of the respective resonator 25, rr is preferably 1 for certain waves

~ l = Ü = 4 ^ T \

or r - r 1

L ijjjt2 +1

or r_r * 1

L u Vjt2 ± 0 x

According to an embodiment not shown in more detail, the resonance body is designed in the form of a cone or a pyramid.

The particular advantage of the pinch, cone and pyramid antenna shapes is that no tuning capacitor, i. no variable capacitor is needed. However, the dimensions and the cone-pyramid angle according to the latter two relationships must be strictly adhered to.

In a preferred embodiment of the invention, the diameter of the resonator 25 corresponds to the wavelength of the signal or its fraction. This diameter is preferably n3, n3 / 2 or tx3 / 4.

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According to a particularly preferred embodiment, there is for each searched material a very specific resonant body 25, which could also be called glass antenna, with the corresponding diameter or circumference for the corresponding frequency or wavelength.

With reference to FIG. 3, a piece of material 46 to be located or to be located, for example of metal, is shown in front of the material-detecting device 1 at a certain distance, which is shown here particularly low for reasons of drawing. The piece of material is at an angle of 0 °. In such a case, a minimum signal is obtained with the antenna in the form of the resonant disc. A similar value results in a 90 ° arrangement. By contrast, a maximum signal is obtained when the piece of material 46 is arranged at 45 ° (shown in dashed lines in FIG. 3). As mentioned, the rotatable body 3 of the polarization angle adjusting tool 24 is rotatable. To determine the signal, a headphone or an electrical measuring device can be connected to the connection 21 in order to directly indicate the frequency and amplitude of the received signal and, if appropriate, the value of the direct current, the position of the sought-after material. Preferably, the printed circuit board has an amplifier circuit and is used in particular for measuring the wavelength and the frequencies of the received signals. The resonance frequencies are usually in the audible range between 20 and 20,000 Hz. However, resonant frequencies occurring outside the audible range can also be determined with the aid of corresponding display devices.

FIG. 22 shows a schematic, partial vertical section through the upper part of the material-detecting device according to another embodiment.

According to this embodiment, three magnetic plates 54 are provided, wherein below the upper magnetic plate 54, a polycarbonate layer 55 is located. This is followed at the bottom of the resonator 25. A further polycarbonate layer 55 is located on the middle magnetic plate 54. In Fig. 22 below the middle magnetic plate 54 is spaced from the latter a polycarbonate plate 56. Below the latter is another resonant body 25, which is formed as a position and polarization angle resonator. Above the lower magnetic plate 54 is again a polycarbonate layer 55. The screw 31 is again formed as in the embodiment shown in Fig. 4 as a hollow screw and surrounded by the Teflon sleeve 35. In this case, however, the upper resonator body 25 has direct contact with the screw 31. In the lower part of the screw 31 is located outside on the Teflon sleeve 35, the rivet 34th

With the help of the three magnetic disks 54 described above, the radiation losses are minimized. The entire assembly ultimately forms preferably a package with self-adhesive magnetic disks and polycarbonate layers. The total diameter 57 in this arrangement is preferably 31 mm, namely exactly n3 mm.

In Fig. 23, a basic circuit 58 in the form of a series resonant circuit is shown schematically. In this case, the resonance body 25 is connected to a first capacitor 59 with 50 to 300 pF, this can also be bridged by an adjustable second capacitor 60 with 0 to 50 pF. The output of both capacitors is connected to a first diode 61 and to a second diode 62. The former is connected on its other side to an amplifier, not shown, second is connected to a resistor 63 with 200 kß. The resistor 63 is further connected to a 9 volt DC power source. The basic circuit shown in Fig. 23 operates at 0 to 8 volts DC. The diodes 61, 62 may be formed as an impedance converter. It is possible to use signal field effect transistors for direct or alternating current instead of the diodes mentioned. The basic circuit is suitable for AC * and DC signals.

Polarization adjustment and measurement may be performed mechanically by pivoting, tilting, rotating the material detection device or magnetically by a static magnetic interference field or electrically directly by means of the capacitor (0-8 V DC voltage), e.g. by means of a coil, by applying to the coil a DC voltage of 0 to 8 volts.

The resonator body is made, for example, of a soft magnetic material, preferably pure iron, pure nickel and their alloys. The resonator body may be made of any metal and / or a semiconductor or piezoelectric material. According to an embodiment, not shown, two opposing magnetic plates are arranged outside the rotatable body of the search antenna polarization instrument whose static magnetic field is generated by a coil.

The initial polarization angle is set with a DC voltage between 0 to 8 volts. The magnetic field of the resonator can be evaluated by means of a Hall or magnetic field sensor, for example manufactured by Philips under the name KMZ 10.

The procedure for measuring is explained in more detail below.

First, the material detecting device 1 is held vertically with the aid of the spirit level 8 and the bladder 9. The polarization angle 24 is set to 0 ° by rotating the rotatable body 3 so that the tip of the marker 10 coincides with the polarization angle 0 ° of the degree scale 13. Subsequently, the detector device is rotated in the vertical position by 360 ° in order to clarify in which rotation angle (azimuth angle) a signal can be obtained taking into account that a maximum signal is obtained when the resonance body, also called rotary antenna, an angle of 45 ° to the sought piece of material, and a minimum signal is obtained when the rotating antenna to the piece of material makes an angle of 0 or 90 °. In the vertical position

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has the detector device, as indicated in FIGS. 1 and 2, an opening angle of 180 °, namely + or -90 °, so that signals can be received only from this opening angle.

Subsequently, the rotary antenna is again rotated so far that the signal is minimal. In this rotational position, the detector device is tilted by 90 ° in the direction of the minimum signal in the horizontal plane and held in this position. By a subsequent check, it can be determined where the signal is minimized by rotating the detector device in different directions in the horizontal plane.

The orientation of a desired piece of material can be determined according to a first variant by cross-bearing. If the detector device is correctly aligned, only a minimal signal results in this position, the same measurement is carried out once again from another location, so that the exact location of the piece of material or generally of the searched object can be determined by the so-called cross-bearing.

The position of the desired piece of material can be determined according to a second variant by a determination of angle and distance. The angle determination takes place in the manner described above; for the distance determination, as previously indicated, a transit time measurement is carried out by the signal transmitted from the rotating antenna, so the resonant body, a pulse superimposed and the duration of the pulse, namely that time is measured, which requires the pulse until it the desired piece of material reflected again arrives at the rotary antenna.

The resonance body may also be formed as a so-called dipole, for example, by two discs are placed next to or above each other. This makes it possible to get twice as strong a signal. Further, the printed circuit board 14 may be provided with potentiometers for adjusting a bias voltage to the capacitor electrodes of the material detector.

Thus, a search antenna polarization instrument is created with which a searched material can be found over a greater distance away.

Claims (13)

claims A search antenna polarizing instrument for a material detecting device (1) comprising a rotatable magnetic disc (23) having body (3) for adjusting the polarization angle (24), a base body (5) connected to the rotatable body (3), which one a resonance body (25) whose upper side (26) is arranged facing the magnetic disk (23) of the rotatable body (3) and which is a transmitting and receiving antenna, - An insulating layer (28), which adjoins with its upper side to the underside (27) of the resonance body (25), a permalloy alloy layer (29) adjoining the underside of the insulating layer (28) and forming a capacitor (30) together with the resonator body (25), a printed circuit board (14) which is electrically connected to the capacitor (30) and has electronic elements (15), the transmitting and receiving antenna being insertable between the material detection device (1) and a piece of material ( 46) to perform a transit time measurement by the time is measured for the purpose of determining the distance between the material-detecting device (1) and the piece of material (46) until the of the resonant body (25) emitted signal from the piece of material (46) coming back again on Resonant body (25) has arrived, wherein the resonator body (25), the insulating layer (28) and the layer (29) centrally penetrated by a screw (31) which is designed as a hollow screw and a nut (32) on an L. -shaped bracket (33) are attached, which receives the printed circuit board (14) and is electrically connected thereto. 2. Search antenna polarizing instrument according to claim 1, characterized in that the rotatable body (3) the upper part (4) of the search antenna polarization instrument (2) and for vertical alignment of the instrument (2) on its upper side (7) a spirit level ( 8) in the form of a circular level. 3. Search antenna polarization instrument according to claim 1 or 2, characterized in that the two-pole resonator body (25), the insulating layer (28) and the layer (29) by means of these parts penetrating, central screw (31), a hollow screw with inner Tuning screw (37), are attached to the printed circuit board (14). 4. Search antenna polarization instrument according to one of the preceding claims, characterized in that the insulating layer (28) made of polycarbonate and the layer (29) is in the form of a magnetic lens. 5. Search antenna polarization instrument according to one of the preceding claims, characterized in that the resonator (25) hair or tubular, rectangular, rectangular-arc, lenticular, part-circular, arcuate, with or without one or more indentations (45) or a combination of the aforementioned Shapes is formed and has a bore (64). 6. Search antenna polarization instrument according to claim 5, characterized in that the one or more notches (45) are shaped like a circle. 7 CH 696 893 A5 7. Search antenna polarization instrument according to one of the preceding claims, characterized in that the resonance body (25) has a length L and a radius r and for the ratio radius / length r / L at certain waves r r ~ L = U = r 1 L yyyy; 2 + i r r 1 1 L u Vtt2 ± 0 k, where U denotes the circumference of the resonator (25). 8. Search antenna polarization instrument according to claim 7, characterized in that the resonance body (25) is in the form of a cone or a pyramid. 9. Search antenna polarization instrument according to one of the preceding claims, characterized in that the resonance body (25) is made of a soft magnetic material, pure iron, pure nickel or their alloys. 10. Search antenna polarization instrument according to one of claims 1 to 9, characterized in that the resonance body (25) is made of a metal and / or a semiconductor or piezoelectric material. 11. Search antenna polarization instrument according to one of the preceding claims, characterized in that outside the rotatable body (3) of the search antenna polarization instrument (2) two opposing magnetic plates are arranged whose static magnetic field is generated by a coil. 12. Search antenna polarization instrument according to one of the preceding claims, characterized in that the initial polarization angle is set with a DC voltage between 0 to 8 volts. 13. Search antenna polarization instrument according to one of the preceding claims, characterized in that the magnetic field of the resonance body (25) can be evaluated by means of a Hall or magnetic field sensor. 8th