WO2016037740A1

WO2016037740A1 - Hand-held measuring device having a nuclear spin resonance sensor for humidity measurement

Info

Publication number: WO2016037740A1
Application number: PCT/EP2015/066156
Authority: WO
Inventors: Reiner Krapf; Klaus Marx; Ulli Hoffmann
Original assignee: Robert Bosch Gmbh
Priority date: 2014-09-12
Filing date: 2015-07-15
Publication date: 2016-03-17
Also published as: EP3191820A1; DE102014218375A1

Abstract

The invention relates to a mobile measuring device (10), in particular a hand-held measuring device, comprising a housing (12), in which at least one sensor device (32), a control device (28) for controlling the sensor device (32), an evaluation device for evaluating measurement signals supplied by the sensor device (32) as well as a device for supplying energy (22) to the measuring device (10) are provided. It is proposed that the sensor device (32) comprises at least one nuclear spin resonance sensor (32') which is provided at least for determining a humidity value of a workpiece (42), in particular in a workpiece (42). The invention further relates to a method for producing such a measuring device (10).

Description

description

title

HAND-HELD DEVICE WITH A HEARTPIN RESONANCE SENSOR FOR HUMIDITY MEASUREMENT State of the art

The present invention relates to a mobile, in particular handheld, measuring device which has a housing in which at least one sensor device, a control device for controlling the sensor device, an evaluation device for evaluating supplied by the sensor device

Measuring signals and a device for supplying power to the meter are provided.

From DE 10 2008 055 196 AI is a device for transmitting and / or receiving electromagnetic high-frequency signals, in particular a

Ultra-wideband sensor unit for a radar device, with at least one planar radiator element, with at least one substrate, which is arranged in the near field of the radiator element, known. The substrate forms a dielectric whose effective dielectric constant is spatially inhomogeneous. In particular, the device for the detection and classification of

Wall moisture can be used.

The mobile measuring device according to the invention, in particular hand-held measuring device, is based on a measuring device with a housing in which at least one sensor device, a control device for controlling the sensor device, an evaluation device for evaluating supplied from the sensor device measurement signals and a device for power supply the meter are provided. According to the invention, the Sensor device at least one nuclear magnetic resonance sensor (NMR sensor), which is provided at least for determining a moisture value of a workpiece, in particular at least for determining a moisture value in a workpiece.

A hand-held measuring device is to be understood here in particular as meaning that the measuring device can be transported only with the hands, in particular with one hand, without the aid of a transport machine, and in particular can also be guided along a workpiece during a measuring process. For this purpose, the mass of the hand-held measuring device is in particular less than 5 kg, advantageously less than 3 kg and particularly advantageously less than 1 kg. Advantageously, the measuring device can have a handle or a grip area with which the measuring device can be guided over an object to be examined, in particular via a workpiece.

It is proposed that the components of the sensor device, the control device, the evaluation device and the device for powering the measuring device are at least partially accommodated in the housing of the measuring device. In particular, the components are housed in their total volume to more than 50%, preferably more than 75% and particularly preferably 100% in the housing of the measuring device. Advantageously, thus, a compact, easily one hand feasible measuring device can be realized. Furthermore, the components can be advantageously protected in this way from damage and environmental influences, for example moisture and dust.

The mobile measuring device has a control device for controlling the sensor device. The control device is to be understood in particular to mean a device with at least one control electronics, the means for communication with the other components of the measuring device, for example means for controlling and regulating the sensor device, and / or means for data processing and / or others which appear expedient to the person skilled in the art Having means. In particular, the control device is provided to at least one operating function parameter of the measuring device as a function of at least one user input and / or one To set the evaluation result of the evaluation unit. The term "intended" should be understood to mean in particular "programmed", "designed" and / or "equipped". By "providing" an object for a particular function, it should be understood, in particular, that the object fulfills and / or executes this particular function in at least one application and / or operating state or is designed to perform the function The control electronics of the control device according to the invention can be understood to mean a processor unit in connection with a memory unit and an operating program stored in the memory unit which is executed during the control process In addition, the control device may be provided in a particularly advantageous manner for controlling the entire measuring device and for enabling it to operate, for which purpose the control device is provided with the other components of the measuring device, in particular the Sensor device, the evaluation device, an input and / or output device and the data communication interface to communicate.

The evaluation device for evaluating measurement signals supplied by the sensor device should be understood to mean at least one device which has an information input for accepting the measurement signals of the sensor device, an information processing unit for processing, in particular evaluation of the assumed measurement signals, and an information output for passing on the processed and / or evaluated Has measuring signals. Advantageously, the evaluation unit has components which comprise at least one processor, a memory and an operating program with evaluation and calculation routines. In particular, the electronic components of the evaluation device can be arranged on a printed circuit board (printed circuit board), preferably on a common board with the control device, particularly preferably in the form of a microcontroller. Furthermore, the control device and the evaluation device may be particularly preferably designed as a single component. The evaluation device is provided to evaluate the measurement signals received from the sensor device and to determine therefrom at least one moisture value in a workpiece. Furthermore, the evaluation and / or the control device can have stored correction and / or calibration tables, which allow evaluation results to be interpreted and / or converted and / or interpolated and / or extrapolated and the measuring device calibrated, in particular with regard to a workpiece material ,

The device for supplying energy to the measuring device is intended to supply the measuring device with electrical energy for commissioning and during operation. Preferably, this device is a power-independent energy storage, in particular a rechargeable battery, a battery, a fuel cell, a capacitor, another, the expert appears reasonable energy storage or a combination / increase of those. In particular, accumulators with a cell chemistry which provides a high power and / or energy density are particularly suitable for supplying energy to the measuring device. These currently include, for example, rechargeable batteries of lithium and lithium-ion cell chemistry, in particular lithium iron phosphate, lithium manganese oxide, lithium nickel cobalt manganese oxide, lithium-nickel-cobalt manganese oxide überithiierte, lithium Sulfur, lithium polymer and lithium-oxygen storage batteries. Preferably, the device for power supply to a releasable positive connection and / or adhesion connection interface. Under detachable should be understood in this context, in particular non-destructively separable. Thus, the device for power supply is preferably removable and interchangeable on the meter can be arranged. Particularly preferably, the removable device for power supply in and / or outside of the meter can be supplied with energy from a power grid and load again.

Under a workpiece in particular contiguous parts of a material should be understood. By way of example and not limitation, it may be a wall, a floor, a ceiling, a screed, an organic structure (in particular parts of a body) and / or a part of a terrain. These materials can, for example, consist in particular of wood, glass, plastic, concrete, stone, brick, plaster, metal, organic materials or similar. In addition, liquids can be analyzed in principle.

According to the invention, the sensor device of the measuring device has at least one nuclear magnetic resonance sensor, which is provided at least for determining a moisture value in a workpiece. The operation of the nuclear magnetic resonance sensor is based on the nuclear physics effect, in which atomic nuclei of a material sample, in particular in the workpiece, absorb and emit electromagnetic alternating fields in a magnetic field. The nuclear magnetic resonance is based on the precession (Larmorpräzession) of nuclear spins of the atomic nuclei in the material sample to the magnetic field lines of a constant, especially static, first magnetic field. In particular, the nuclear spins of the atomic nuclei in the material sample are aligned by the first magnetic field. If energy in the form of a second electromagnetic field, in particular an alternating field, for example a pulsed magnetic field, is radiated onto the atomic nuclei which resonate with the Larmor precession of their nuclear spins (energy quanta), then the atomic nuclei can orient their spins relative to the first magnetic field by absorption to change that energy. The second incident magnetic field therefore serves to excite the nuclear spins, which change their nuclear spin states while absorbing energy. Equivalently, the emission of energy quanta results from a return of the excited nuclear spins to another, lower energy level, to the emission of an alternating electromagnetic field, which can be observed by a device for detecting a magnetic field change, in particular by means of an antenna and / or a coil.

Advantageously, the nuclear magnetic resonance sensor allows atomic nuclei to excite the material sample in the workpiece by means of electromagnetic alternating fields and to generate an output signal due to a nuclear magnetic resonance effect. With a suitable choice of the operating parameters of the nuclear magnetic resonance sensor can be concluded by means of the amplitude and / or relaxation times of the response signal directly to the amount of hydrogen atoms in the examined volume, from which information about the moisture present in the workpiece can be evaluated. Excitation of atomic nuclei should in particular be understood as meaning that the energy of the irradiated electromagnetic fields, in particular alternating fields, causes a change in the nuclear spins of the atomic nuclei. Furthermore, it is assumed in the following that in particular variable magnetic fields are coupled to electric fields (see Maxwell equations), so that no distinction is made between the electric field and the magnetic field. To excite nuclear magnetic resonance effects, it is particularly important to the energy transmitted by an irradiated electromagnetic radiation. Advantageously, this energy can be transmitted by means of pulsed electromagnetic fields.

To carry out the measurement, the mobile measuring device, in particular the nuclear magnetic resonance sensor contained therein, is brought close to the workpiece to be examined.

The determination of a moisture value in a workpiece should in particular be understood to derive statements from the nuclear magnetic resonance data obtained, inter alia, a relative and / or absolute moisture content and / or a moisture gradient into the workpiece and / or bonding states of the moisture-forming water and / or temporally dynamic processes of moisture-forming water. Particularly advantageously, the mobile measuring device allows the determination of moisture values in a workpiece without destroying the workpiece. In particular, the measuring method is a non-destructive, in particular contactless, measuring method, i. In one embodiment of the measuring device according to the invention, a moisture value can also be obtained without any contact of the measuring device with the sample to be measured, if appropriate also without contact with the workpiece to be examined. The positioning of the measuring device, in particular the nuclear magnetic resonance sensor contained therein in the immediate vicinity of the workpiece surface allows the determination of moisture values up to a material depth of a few centimeters into the workpiece.

For the particular absolute determination of moisture values, a calibration of the measuring device, in particular a calibration of the Sensor device to be provided. For example, a calibration measurement, which is performed after switching on the meter, on a pure water sample (eg glass filled with water) to determine a maximum humidity (corresponding to 100%) and thus be carried out to calibrate the meter. All subsequent measurements, in particular

Measurements on a workpiece to be examined are then evaluated in relation to this calibration measurement. Furthermore, when the volume examined by the sensor device is known, an absolute humidity and / or volumetric quantities, in particular a concentration, a volume percentage information or the like, can be evaluated.

In addition to the determination of moisture values, the evaluation device may be formed from the measurement signals of the nuclear magnetic resonance sensor at least one relative and / or absolute hydrocarbon content and / or binding states of chemical compounds and / or concentration gradients of a material into the workpiece and / or time-dynamic chemical processes Evaluate compounds, and / or other structurally relevant parameters, in particular salinity, composition, inhomogeneities, material inclusions, densities and / or porosities of the material or materials of a workpiece, in particular evaluated depth-resolved.

Thus, according to the invention, the mobile measuring device can likewise be used to comprehensively characterize a workpiece with regard to material inclusions, material inhomogeneities and / or other material properties.

Statements about the relative and / or absolute hydrocarbon content and concentration gradients in the workpiece allow a reliable evaluation of a workpiece, in particular with regard to processability (machinability, drillability), strength, loadability as well as structurally different materials (inclusions) and the like.

Statements on the bonding states of the enclosed material also allow to determine which shape, in particular which material of material inclusion it is. For example, let yourself up this way advantageous to detect and distinguish inclusions such as metals, wood and plastics. Furthermore, statements can be made about the types of plastic enclosed, as well as, for example, statements about whether plastic pipes are filled with water.

With the recording and evaluation of time-dynamic processes of chemical compounds, processes such as migration, convection and migration of material inclusions can be investigated. Conclusions on a possible flow behavior can be derived from it.

Other structurally relevant parameters which can be evaluated with the evaluation device of the mobile measuring device include, in particular, salinity, density and / or porosity of the material of the workpiece, but also further parameters that appear reasonable to the person skilled in the art.

In an advantageous embodiment of the measuring device according to the invention, an input device for entering operating parameters is present, in particular in the housing of the measuring device.

An input device should in particular be understood to mean a device which is intended to accept at least one piece of information from an operator of the measuring device (in particular user interface) and / or another device via an acoustic, optical, gesture-based and / or tactile input and to the Forward control device of the meter. For example, the input device may consist of an actuating element, a keyboard, a display, in particular a touch display, a voice input module, a gesture recognition unit and / or a pointing device (for example a mouse). In addition, the input device may additionally be present outside of the measuring device, for example in the form of an external data device such as a smartphone, a tablet PC, a PC, or in the form of another external data device which appears expedient to a person skilled in the art and has the data communication interface Control device of the measuring device is connected. Working parameters designate all necessary and / or meaningful operating parameters of the measuring device, in particular for its control, as well as parameters relating to the evaluation of the measuring results.

In an advantageous embodiment of the mobile measuring device, an output device for outputting operating parameters and / or evaluation results is present, in particular in the housing of the measuring device.

The output device should be understood to mean at least one means which is provided to output at least one alternating information acoustically, optically and / or tactilely to an operator. This can be realized for example by means of a display, a touch display, a sound signal, a change of an operating parameter, a vibration generator and / or an LED display. In particular, information to be output, for example evaluation results and / or information regarding an operating state of the measuring device, can also be output to a machine control, in particular also the control device of the sensor device, and / or, in particular to increase user comfort, to a data processing system. The latter comprises at least one output of information to an external device such as a smartphone, a tablet PC, a PC and another, to a professional appear appropriate sense external data device, which is connected via a data communication interface with the evaluation of the meter.

Thus, both the input device and the output device can advantageously be accommodated directly in the housing of the mobile measuring device or alternatively also be outsourced and realized, for example, via external devices. The latter possibility of realization explicitly includes the control, evaluation and output of the measurement results via wired and / or wireless external systems such as remote controls, computer controllers, tablet PCs and / or other mobile devices such as mobile phones, smartphones etc. In an advantageous embodiment of the mobile measuring device, the input device and / or the output device are arranged on a first side of the housing of the measuring device. Housing side means in particular a measuring device to its surroundings limiting outer wall of the housing. By "accommodated on a housing side" is meant that the input device and / or the output device is inserted, applied or otherwise attached to the first side of the housing in the surface thereof. In particular, the housing itself may also be part of the input or output device.

Advantageously, the first side of the housing faces the operator when using the measuring device.

In an advantageous embodiment of the mobile measuring device, the nuclear magnetic resonance sensor of the mobile measuring device has a first device for generating a first magnetic field, in particular a magnetic field with a defined field gradient, a second device, in particular a radio-frequency coil and / or an antenna, for generating a second, the magnetic field superimposed on the first magnetic field, wherein the control device has at least one control unit for controlling the second device, wherein the control unit is provided in particular for modifying the second magnetic field, in particular for generating pulse sequences.

The first magnetic field generated by the first device serves to align the nuclear spins of the atomic nuclei present in the material of the workpiece in such a way that the nuclear spins, based on their magnetic nuclear spin moment, align themselves with the magnetic field lines of the magnetic field, in particular precisions around the magnetic field lines of the magnetic field. An excitation of the nuclear spins occurs as a result of an irradiation of energy in the form of an electromagnetic field generated by the second device, in particular an alternating electromagnetic field, for example a pulsed magnetic field. The first device for generating a first magnetic field, in particular with a defined field gradient, may, in particular, be understood as meaning devices such as permanent magnets, electromagnets, coil devices. The magnetic field generated by the first device is typically designated B ₀ .

In principle, the same means can be understood as the second device for generating a second magnetic field, but this second device is advantageously realized by means of a high-frequency coil and / or an antenna. Particularly advantageously, the high-frequency coil is operated at a frequency in the megahertz range. In particular, the frequency is below 900 megahertz, preferably below 200 megahertz, and more preferably below 50 megahertz.

The control unit for controlling the second device, i. For controlling preferably the radio-frequency coil, it is possible to generate pulse sequences of the second magnetic field, so that the second magnetic field generated by the second device can be modified in time and location. By means of the pulse sequences, the nuclear spins of the atomic nuclei of the material present in the examined workpiece can be excited in a particularly advantageous manner by electromagnetic alternating fields for the absorption and emission of energy quanta, in particular to resonance.

In an advantageous embodiment of the measuring device according to the invention, the nuclear magnetic resonance sensor has a device for detecting a magnetic field change, in particular a receiving coil for detecting a magnetic field change, which makes it possible to conclude magnetic-field changes caused by magnetic resonance relaxation to material-specific characteristics.

Advantageously, with the device for detecting a magnetic field change, a nuclear magnetic resonance effect of the nuclear spins of the atomic nuclei present and excited in the workpiece can be detected as a result of influencing the first and / or the second magnetic field. A flip-over of the nuclear spins of the atomic nuclei, in which an electromagnetic field is emitted, can be particularly advantageously be detected by means of a receiving coil in the form of a voltage induced by the magnetic field variation and / or an induced current. This voltage and / or this current can be forwarded to the evaluation device for evaluation of the nuclear spin signal.

In an alternative embodiment of the measuring device according to the invention, the receiving coil can also be realized by the high frequency coil of the second device for generating the second magnetic field. In this case, the resonance of the nuclear spins of the atomic nuclei becomes noticeable in that a folding of the nuclear spins, followed by an emission of an electromagnetic field, induces in the coil a voltage (equivalent to a current) which overlaps with the applied AC voltage, so Influences can be detected on the power required to operate the high-frequency coil power.

In a particularly advantageous embodiment of the measuring device according to the invention, the first magnetic field generated by the first device of the nuclear magnetic resonance sensor is aligned substantially parallel to a second housing side of the measuring device and the magnetic field generated by the second device substantially perpendicular to the first magnetic field.

The second housing side is in particular a substantially planar outer wall of the housing, which limits the measuring device to its surroundings. In particular, the second side of the housing faces the workpiece to be examined when the measuring device is used. Advantageously, the second side of the housing of the input device and / or the output device receiving first side of the housing opposite the device and is thus facing away from an operator when using the meter.

The orientation of the first magnetic field can be generated by at least two permanent magnet poles (north, south) of a permanent magnet, in particular if the poles are in a north-south orientation parallel to and in the vicinity of the second housing side. This arrangement can be especially structurally simple to realize by using a horseshoe magnet.

The first magnetic field used to align the nuclear spins of the atomic nuclei present in the material sample has in particular one

Magnetic field strength of more than 0.1 Tesla, preferably more than 1.5 Tesla and more preferably more than 5 Tesla. In particular, strong permanent magnets are suitable for generating this magnetic field, for example produced from ferrites or preferably as iron-cobalt-nickel alloy or particularly preferably as neodymium-iron-boron or samarium-cobalt alloy.

Alternatively, the magnetic field alignment of the first magnetic field can be realized by at least two permanent magnets, which are aligned perpendicular to the surface of the second side of the meter anti-parallel, in particular within the housing, and in the vicinity of the second housing side. The magnetic field lines running from the north pole of the first permanent magnet to the south pole of the second permanent magnet can be considered to be substantially parallel to the second housing surface of the measuring device when the two permanent magnets are aligned at a distance from one another. In particular, "substantially parallel" is understood to mean that a first region exists in which the magnetic field lines describing the first magnetic field can be considered to be nearly parallel, In particular, in this first region the deviation of the magnetic field lines from a theoretical parallel is less than 20 degrees , advantageously less than 10 degrees, and more preferably less than 5 degrees.

The second magnetic field, which is substantially perpendicular to the first magnetic field and thus also to the second housing side, can be produced in a particularly advantageous embodiment with a coil and / or with an antenna, in particular with a high-frequency coil. For this purpose, the coil is arranged in particular in a plane parallel and in the immediate vicinity of the surface of the second housing side, preferably in the interior of the housing, possibly also on the outside of the housing or in the housing wall. The magnetic field lines of the magnetic field generated by the current-carrying coil run in the vicinity of the coil perpendicular to the coil plane. Under "essentially perpendicular to the first magnetic field "is to be understood here as meaning that a second region exists in which the magnetic field lines describing the second magnetic field can be considered to be nearly perpendicular to the magnetic field lines of the first magnetic field second magnetic field from the vertical less than 20 degrees, advantageously less than 10 degrees, and more preferably less than 5 degrees, more preferably the first and second regions coincide.

The magnetic field orientation of the first magnetic field can also be achieved by two parallel to the second side of the housing and collinearly arranged permanent magnets, i. in north-south / north-south sequence, wherein between these two permanent magnets, a high frequency coil is located, the winding plane is collinear to the extension direction of the permanent magnets and parallel to the second side of the housing. The described arrangement is also positioned in proximity to the second side of the housing.

By suitable positioning of the devices for generating the magnetic fields in the vicinity of the second side of the housing, it is advantageously achieved that the region in which the two magnetic fields overlap is at least partially outside the housing of the measuring device, so that an engagement of the magnetic fields in the workpiece to be examined is possible.

In an alternative embodiment, the first magnetic field generated by the first device of the nuclear magnetic resonance sensor is aligned substantially perpendicular to a second side of the housing of the measuring device and the second magnetic field generated by the second device substantially perpendicular to the first magnetic field.

In a particularly advantageous embodiment of the measuring device according to the invention, the first device for generating the first magnetic field and / or the second device for generating the second magnetic field are at least partially surrounded by at least one magnetic shield. This magnetic shielding, which may consist in particular of ferromagnetic materials and / or mu-metal and / or electrically conductive elements, allows the influencing of the course of the magnetic field lines and thus an optimization of the area in which the magnetic fields are superimposed. The latter means in particular a reduction or enlargement of the

Overlay area and / or a homogenization of the magnetic fields and / or parallelization of the magnetic field lines and / or any other influence on the magnetic field gradients of both magnetic fields. By Mu metal (also: μ metal) is meant a soft magnetic alloy of high magnetic permeability, which is suitable for shielding magnetic fields.

Particularly advantageously, this magnetic shielding can also be used to at least partially shield the magnetic fields used by the nuclear magnetic resonance sensor against other interfering influences, in particular electromagnetic radiation, and / or to shield components of the mobile measuring instrument itself at least partially from electromagnetic radiation of the internal nuclear magnetic resonance sensor.

Furthermore, it is proposed that the nuclear magnetic resonance sensor has at least one device for homogenizing the magnetic fields generated by the first and / or second device. Homogenization of a magnetic field is to be understood in particular as meaning that the magnetic field lines describing the magnetic field and its local magnetic field strength are subject to only slight, ideally no variations and in particular have no field distortions. In particular, a coil can be understood by this device, also called a shim coil, with the aid of which correction fields are generated which superimpose the magnetic fields generated by the first and the second device and, if suitably controlled, homogenize and / or influence to the desired extent. In a particularly advantageous embodiment of the mobile measuring device, the second device of the nuclear magnetic resonance sensor for generating the second magnetic field, in particular the radio-frequency coil, is realized in a non-destructively non-destructive manner.

In this way it can be realized that coils with different

Characteristics, in particular numbers of turns, geometry and wire thicknesses, non-destructively exchanged by a user of the meter and then used. Advantageously, by suitable choice of the coil, the magnetic fields generated by the second device can be varied and adapted to the required operating conditions, in particular the material of the workpiece to be examined. Furthermore, it can be achieved that the region in which the first and the second magnetic field are superimposed is shifted in position and / or modified in terms of its geometry.

To realize the interchangeability, the measuring device can have access to the second device of the nuclear magnetic resonance sensor, in particular on the second side of the housing. In one embodiment of the mobile measuring device, the magnetic fields of the nuclear magnetic resonance sensor define a first sensitive region of the nuclear magnetic resonance sensor, in particular a layer-shaped region which extends substantially parallel and spaced from the second housing side outside the housing of the measuring device.

This sensitive area lies in particular in the superposition field of the first and the second magnetic field. Depending on the frequency (Larmor frequency) of the irradiated electromagnetic field and the static magnetic field strength of the first magnetic field, the sensitive region is ideally defined by a surface on which the magnetic field strength of the first magnetic field is constant and in particular has a defined amount. In reality, the surface is actually layered due to inaccurate, ie not discrete, frequencies. Furthermore, since the magnetic field lines are not exactly parallel, the sensitive region can consequently be curved along the magnetic field lines and / or inhomogeneous, in particular inhomogeneous with respect to its layer extent. In this way, it can be achieved particularly advantageously that by positioning the mobile measuring device on a workpiece surface, with the second housing side of the measuring device being positioned in the immediate vicinity of the surface of the workpiece to be examined, the magnetic fields penetrate into the workpiece and the sensitive region of the nuclear magnetic resonance Sensor comes to rest in the workpiece.

In an alternative and / or additional embodiment of the measuring device, the sensor device can be operated such that the sensitive area in the superposition field of the two magnetic fields within the housing, in particular in the interior of the nuclear magnetic resonance sensor, preferably centrally between the two permanent magnet poles spanning the first magnetic field, located. In this way, a measuring device can be realized in a simple manner in which material samples for measurement can be introduced. For example, in this way material samples can be introduced into the measuring device by means of a sample tube through an opening in the second housing side of the measuring device such that they come to lie centrally between the two permanent magnet poles spanning the first magnetic field and thus in the sensitive region of the nuclear magnetic resonance sensor. Particularly advantageously, it can be provided that it is possible to switch over between the different arrangements of the sensitive area, in particular between a positioning of the sensitive area inside and outside the housing of the measuring device. Such a switching can advantageously be realized mechanically (for example by shielding and / or repositioning the first and / or the second device for generating the first or second magnetic field in the measuring device) or electronically (for example by changing the frequency in the high-frequency coil).

If the volume defined by the sensitive area, ie the volume of the material of the workpiece which is examined in a measurement, is known, absolute values and, in particular, also volumetric variables of the moisture value, for example a concentration, volume percent information or the like, be evaluated. That by the sensitive Area defined volume can be advantageous due to the design and / or be known by an instrumental measurement.

It is further proposed that the sensitive region of the nuclear magnetic resonance sensor along a perpendicular to the second

Can shift housing side of the meter outside the housing, in particular mechanically and / or electronically move, advantageously by 1 cm, more preferably by 2 cm, in particular by 3 cm. The shift of the sensitive area can thereby be advantageous

Modification of the magnetic fields, for example by changing their geometry and / or homogeneity by means of a coil (so-called shim coil) or a (movable) magnetic shielding, particularly advantageously by changing the frequency of the radio-frequency coil, as well as by mechanical method of nuclear magnetic resonance sensor in Enclosure of the meter can be achieved. Consequently, with constant positioning of the measuring device within the workpiece, the sensitive region can be displaced in such a way that a depth-resolved measurement can be realized in a simple and particularly economical manner.

In a particularly advantageous embodiment of the mobile measuring device according to the invention, the second housing side of the measuring device faces the first housing side accommodating the input device and / or the output device and is in particular arranged at the rear of the device.

In this way, it can advantageously be achieved that the measuring device, when positioned with the sensitive area toward a workpiece, in particular with the second housing side adjacent to the workpiece, can be operated via the input and / or output devices received on the first housing side of the measuring device or measurement results can be read.

It is proposed that in a further advantageous embodiment of the mobile measuring device, the evaluation device is designed for the evaluation of measurement signals supplied by the sensor device, and in particular is provided to evaluate at least one amplitude and / or a relaxation time of a measurement signal resulting from the excitation of nuclear spins in a workpiece by the magnetic field of the second device. Particularly advantageous is the evaluation device for the evaluation of the

Sensor device provided by measuring signals formed by determining the number of IH atoms in the workpiece at least a relative and / or absolute moisture content and / or a moisture gradient into the workpiece and / or bonding states of the moisture-forming water and / or time-dynamic processes of the Moisture-forming water and / or other structurally relevant parameters, in particular salinity, composition, density and / or porosity of the material of the workpiece to evaluate.

According to the invention, the mobile measuring device can thus be used to comprehensively characterize a workpiece in terms of moisture. Statements about the relative and / or absolute moisture content as well as a moisture gradient into the workpiece allow a reliable evaluation of a workpiece, in particular with regard to processability, dryness, mold danger, strength, load capacity and other variables dependent on the moisture.

In addition, statements about the binding states of the moisture-forming water allow one to ascertain whether the moisture is free water, capillary water, physi- or chemisorbed water, water of crystallization, etc. Further conclusions regarding a possible drying behavior and / or drying result can be derived from this.

With the recording and evaluation of temporal-dynamic processes of the moisture-forming water, processes such as migration, convection and migration of water, in particular of water fronts in the material can be investigated. Conclusions on a possible drying or Durchnässungsverhalten and / or on a drying result can be derived therefrom. Other structurally relevant parameters which can be evaluated with the evaluation device of the mobile measuring device include, in particular, salinity, composition and / or mixing ratio of the material of the workpiece and its density and / or porosity, but also other parameters which appear reasonable to the person skilled in the art.

In a further advantageous embodiment of the mobile measuring device according to the invention, a position-determining device is provided for detecting at least one instantaneous position and / or orientation of the measuring device, in particular with respect to the workpiece.

For this purpose, the position-determining device may in particular comprise one or more sensors from a group of sensors, which comprises at least inclination, angle, distance, translation, acceleration and rotational rate-sensitive sensors. Furthermore, a position determination can also be realized with other means that appear appropriate to a person skilled in the art.

For example, the position-determining device can be realized using rolling elements, in particular using wheels arranged on the housing of the measuring device, which receive the change in position relative to the workpiece during the movement of the measuring device. Since the distance between measuring device and workpiece should preferably be minimized to increase the penetration depth of the magnetic fields into the workpiece, the position-determining device can also be provided as optical displacement transducer, which is arranged in the housing side facing the workpiece to be examined when the measuring device is used ,

It is further proposed that the evaluation device for evaluating measurement signals supplied by the sensor device is designed to evaluate measurement signals of the sensor device as a function of the position and / or orientation of the measuring device, in particular with respect to the workpiece. Thus, it can advantageously be achieved that evaluated parameters can be correlated with a position of the measuring device on the workpiece. Furthermore, by successive measurement of a workpiece, multidimensional matrices or maps in which measurement specifications for positions and / or orientations of the measuring device, in particular with respect to the workpiece, are recorded can be created and / or evaluated. This can be used particularly advantageously for generating a representation of the evaluated measurement signals in the form of a map of the workpiece. In a further advantageous embodiment of the mobile measuring device, at least one storage device is provided for storing measurement results and / or operating parameters.

This memory device can comprise all forms of external and internal electronic, in particular digital, memories, in particular also

Memory chips such as USB sticks, memory sticks, memory cards, etc.

In addition, it is proposed that the control device and / or the evaluation device of the measuring device according to the invention has a data communication interface for, in particular, wireless communication, by means of which the measuring device can transmit and / or receive measurement results and / or working parameters.

Preferably, the data communication interface uses a standardized communication protocol for a transmission of electronic, in particular digital data. Advantageously, the data communication interface comprises a wireless interface, in particular, for example, a WLAN, Bluetooth, infrared, NFC, RFLD interface or another wireless interface which appears expedient to a person skilled in the art. Alternatively, the data communication interface can also have a wired adapter, for example a USB or micro USB adapter.

Advantageously, by means of the data communication interface measurement results and / or working parameters of the meter to an external data device, such as a smartphone, a tablet PC, a PC, a printer or further to a professional appear reasonable sense external devices are sent or received by them. By means of the embodiment according to the invention, a transfer of data can advantageously be made possible, which can be used for a further evaluation of measurement signals detected by the measuring device. Furthermore, various additional functions can advantageously be enabled and integrated, which in particular also require direct communication with smartphones (in particular via programmed apps) or similar portable data devices. These can include, for example, automatic mapping functions, firmware updates, data postprocessing, data preparation, data synchronization with other devices, etc.

Furthermore, it is proposed that the control device of the measuring device has an operating mode in which information on a workpiece can be specified by user inputs and / or made available to the measuring device.

Under operating mode, in particular, an information processing, an information output or an information input should be designated, in connection with which the control device applies an operating program, control routines, control routines, evaluation routines and / or calculation routines.

Information about a workpiece may relate, for example, to the material of the workpiece, its physical or chemical properties, and any other specifications that appear appropriate to a person skilled in the art.

For an advantageous embodiment, it is proposed that the control device of the measuring device has an operating mode in which output parameters of the output device can be specified and / or made available to the measuring device.

Output parameters are to be understood as all specifications relating to the output, in particular parameters of interest to the user, types of output (eg as number, graphics, map, converted equivalent quantities), conversion options, error displays, correction factors, etc. In a further embodiment of the measuring device according to the invention, the sensor device has at least one further sensor from a group of sensors which at least induction, capacitance, ultrasonic, temperature, humidity, radiation, tilt, angle, magnetic field, acceleration and rotational rate sensitive sensors includes.

In this way, advantageously, a combination of similar or complementary measuring instruments can be integrated in the measuring device according to the invention. For example, the nuclear magnetic resonance sensor can be expanded particularly advantageously with induction- and / or capacitance-sensitive sensors. Preferably, the signals of the further sensors are also evaluated by the evaluation device for evaluating supplied from the sensor device measurement signals. The evaluation results of the various sensors can advantageously be correlated with one another; in particular, measured values obtained by means of the further sensors can be used to correct and / or optimize and / or calibrate the measurement results determined by the nuclear magnetic resonance sensor. Alternatively, an output of the further measurement results as a supplementary measured value and / or complementary value by means of

Output device take place.

According to the invention, a method for operating a measuring device, in particular a method for operating a measuring device for determining at least one moisture value of a workpiece, in particular one

Humidity value proposed in a workpiece, which is characterized by at least the following steps:

Generating a first magnetic field in the workpiece by means of a first, in particular arranged in the meter, device

Generation of high-frequency pulses in the workpiece by means of a second

Device of the measuring device, in particular by means of a high frequency coil

Detection of at least one amplitude and / or one relaxation time of a

Measuring signal resulting from the excitation of nuclear spins in the workpiece, in particular by means of an induced current in a receiving coil and / or an induced electrical voltage Extraction of Larmor frequencies from a measurement signal, in particular from an electrical current induced in a receiver coil and / or from an electrical voltage induced in a receiver coil

Evaluation of measurement signals of the nuclear magnetic resonance sensor for determining at least one moisture value of the workpiece, in particular of a moisture value in the workpiece, by means of an evaluation device arranged in particular in the measuring device.

drawings

The invention is explained in more detail in the following description with reference to exemplary embodiments illustrated in the drawings. The drawing, the description and the claims contain numerous features in combination. The person skilled in the art will expediently also consider the features individually and combine them into meaningful further combinations. Like or similar reference numerals in the figures indicate the same or similar elements.

Show it:

Figure 1 perspective view of a Ausgestaltu

inventive mobile measuring device,

FIG. 2 shows a view of the first housing side of an embodiment of the invention

measuring device according to the invention,

Figure 3 is a schematic side view of an embodiment of

measuring device according to the invention,

FIG. 4 a shows a schematic and simplified illustration of an embodiment of the components forming the nuclear magnetic resonance sensor and of the magnetic fields generated therewith,

Figure 4b schematic and simplified representation of an alternative

Embodiment of the nuclear magnetic resonance sensor forming components and the magnetic fields generated therewith,

Figure 5 perspective view of the second side of a housing

Embodiment of the mobile measuring device according to the invention Description of the embodiments

Figure 1 and Figure 2 show two views of an exemplary embodiment of the hand-held measuring device 10 according to the invention in a perspective view or in a simplified, schematic plan view.

The exemplified hand-held measuring device 10 has a housing 12, an input device in the form of actuating elements 14, suitable for switching the hand-held measuring device on and off, for starting and configuring a measuring process and for entering operating parameters, as well as a

Output device for output of operating parameters and / or evaluation results in the form of a display 16. The hand-held measuring device 10 has a handle 18 for transporting and guiding thereof. The handle 18, the actuating elements 14 and the display 16 are located on a first housing side 20 of the measuring device 10 (also "front"), which is typically used when operating the measuring device facing the user.

For supplying energy to the hand-held measuring device 10, the device has a second housing side 40 (hereinafter also referred to as the rear side of the measuring device) on the rear side of the housing 20 opposite the first housing side 20

Recess on, which is preferably suitable for receiving power supply independent energy storage 22, in particular batteries or rechargeable batteries. The device presented by way of example has lithium-ion batteries whose high energy and power density is advantageously suitable for supplying power to the measuring device. In an alternative embodiment, the

Energy storage 22 may be housed in the handle 18 of the measuring device 10. Preferably, the device for power supply to a releasable positive connection and / or traction connection interface, so that the energy storage 22 (in general, more) detachable and interchangeable can be arranged. In addition, the energy storage 22 in and / or outside of the meter can be supplied with power from a power grid and charge.

The position-determining device of the hand-held measuring device comprises in the exemplary embodiment four wheels 24, by means of which the hand-held measuring device 10 is moved along the surface 44 of a workpiece 42 can be moved (see Fig. 3). Sensors that are sensitive to rotation of the wheels 24 detect movement of the measuring device 10 and thus allow measurement results related to a position of the measuring device, in particular with respect to the workpiece 42 to set. In an alternative embodiment of the measuring device 10, the position-determining device instead of the wheels, for example, have an optical displacement sensor. For more precise position determination, additional sensors, in particular inclination, angle, translation, acceleration and rotational rate sensitive sensors, may also be present. After placing the hand-held measuring device 10 on the surface 44 of a workpiece 42 to be measured, for example on a wall or on a concrete floor, the position change of the hand-held measuring device is determined as a result of a method of the device on the workpiece. These position data are forwarded to an evaluation device 30 for further evaluation.

On a support member 26, in particular a system board or circuit board within the housing 12, are further components of the measuring device, in particular a sensor device 32 with a nuclear magnetic resonance sensor 32 ', a control device 28 for controlling the sensor device 32, an evaluation device 30 for the evaluation of the Sensor device 32 supplied measurement signals, as well as a connected to the control and / or evaluation device data communication interface 54 housed (see in particular Figure 2).

The nuclear magnetic resonance sensor 32 ', which is explained in detail in FIGS. 4 a and 4 b, is provided for exciting a nuclear magnetic resonance in atomic nuclei of the material of the workpiece 42. According to the invention, the measured resonance signal is used at least for the nondestructive determination of a moisture value in the workpiece 42, ie for the determination of information including a relative and / or absolute moisture content, a moisture gradient into the workpiece, binding conditions of the moisture forming water and / or temporally dynamic processes of moisture-forming water. The control device 28 has control electronics comprising means for communication with the other components of the measuring device, for example means for controlling and regulating the sensor device 32 and the measuring device. In particular, the control device 28 comprises a unit with a processor unit, a memory unit and an operating program stored in the memory unit. The control device 28 is provided to set at least one operating function parameter of the measuring device as a function of at least one input by the user, by the evaluation device and / or by the data communication interface.

The evaluation device 30 for evaluating measurement signals supplied by the sensor device 32, if necessary also for evaluating measurement signals of further sensor devices of the hand-held measuring device 10, has in particular an information input, an information processing and an information output. Advantageously, the evaluation device 30 consists at least of a processor, a memory with a stored and executable operating program and allows to evaluate at least one measurement signal of the nuclear magnetic resonance sensor 32 'and to determine a moisture value based on the workpiece. Particularly advantageously, the evaluation device has stored correction and / or calibration tables, which allow the evaluation results to be interpreted, converted, interpolated and / or extrapolated and the measuring device, in particular the evaluation routines, calibrated with respect to a workpiece material. The evaluation results are output by the evaluation device 30 for further use via the control device 28 either directly to a user of the measuring device 10 or for sending the data to the data communication interface 54.

For measuring a nuclear magnetic resonance signal of a workpiece 42, in particular for determining a moisture value in this workpiece, the measuring device 10 with its second side of the housing 40, ie the back of the device, in the immediate vicinity of the workpiece 42, in particular in contact with the surface 44, positioned. In this case, the magnetic fields 34, 36 generated by the nuclear magnetic resonance sensor 32 'penetrate through the second housing side 40 the measuring device 10 from and into the workpiece 42, wherein the sensitive area 38 comes to lie in the workpiece (see in particular Figure 3). Magnetic field changes due to a nuclear magnetic resonance effect of the nuclear spins of the atomic nuclei excited in the material of the workpiece 42, ie caused by absorption and / or emission of electromagnetic fields by the atomic nuclei accompanying a change in their energy states, can be detected by means of a receiving coil 68 of the nuclear magnetic resonance sensor 32 ' , This measurement signal, in particular its amplitude and relaxation times, is forwarded to the evaluation device 30, from which it is evaluated and processed by means of evaluation routines and to a

Output device 16 is forwarded. The evaluated measurement result is displayed to the user on the display 16 and can alternatively be sent via the data communication interface 54 to another data processing device. The output on the display 16 may be graphically, numerically and / or alphanumerically, for example in the form of a measured value, a

Trace, a waveform, a time course, as image data or in a gradient representation and in a combination derer done. Alternatively or additionally, a display is possible by means of a signal display, in particular, for example, a light-emitting diode which evaluates a target variable, for example via color coding (for example red, yellow, green).

The positioning of the measuring device 10, in particular of the magnetic resonance sensor 32 'contained therein, in the immediate vicinity of the workpiece surface 44 enables the determination of moisture values up to a material depth of a few centimeters into the workpiece 42.

FIG. 3 shows the embodiment according to the invention of the hand-held measuring device 10 of FIGS. 1 and 2 in a simplified schematic side view. The nuclear magnetic resonance sensor 32 'comprises two devices for generating magnetic fields, in particular a permanent magnet arrangement

4a, 4b), which generates a first magnetic field 34, and a high-frequency coil 48 (see FIG. 4a), which generates a second magnetic field 36. The nuclear magnetic resonance sensor 32 'is configured such that the first magnetic field 34 is aligned substantially parallel to the second housing side 40, while the second magnetic field 36 is substantially perpendicular to the second magnetic field Magnetic field lines of the first magnetic field 34 is aligned. The two magnetic fields are superimposed in an extended area, in which, in particular, the sensitive area 38 of the nuclear magnetic resonance sensor 32 'is also located as a layered area in particular. The hand-held measuring device 10 is positioned with the second housing side 40 in close proximity to a workpiece 42 to be examined so that the distance between the second housing side 40 and the workpiece surface 44 is minimized. In this way, it is achieved that the magnetic fields 34, 36 penetrate into the workpiece and the sensitive area 38 comes to lie in the workpiece 42.

By varying the second magnetic field generated by the second device, ie, in particular by varying the high-frequency coil 48 and / or varying the frequency and / or variation of the current and / or variation of the voltage in the high-frequency coil, it is possible to determine the sensitive area 38 to change in its distance from the second side of the housing 40 and thus to modify the distance of the sensitive area 38 in the workpiece to the workpiece surface 44. Alternatively and / or additionally, the nuclear magnetic resonance sensor 32 'in the housing 12 of the hand-held device 10 can be repositioned such that the distance of the nuclear magnetic resonance sensor 32' to the second housing side 40 is changed and consequently the distance of the sensitive area 38 in the workpiece 42 its workpiece surface 44. In this way, it is particularly advantageous to create depth profiles of the parameters to be evaluated, in particular the moisture values. For example, it is possible to use a depth profile to determine the moisture in a workpiece 42 about the drying behavior over time in the workpiece

To hit workpiece 42.

FIG. 4 a shows in a simplified and schematic representation the components of an embodiment of the nuclear magnetic resonance sensor 32 'according to the invention. Two perpendicular to the second

Housing side 40 and antiparallel to each other arranged permanent magnets 46, 46 'generate a first, in particular static, magnetic field 34, which extends substantially parallel to the surface of the second side of the housing 40. This first magnetic field provided for aligning the nuclear spins of the atomic nuclei present in the material sample has, for example, in particular one Magnetic field strength of 0.5 Tesla, wherein the permanent magnets are made of a neodymium-iron-boron alloy. The second device for generating the second magnetic field is formed by a high frequency coil 48 in this embodiment. As soon as current flows through this coil, an electromagnetic field, in particular the second magnetic field 36, is induced.

The two magnetic fields overlap in a region which lies substantially outside the housing 12 of the measuring device 10. The sensitive region 38 of the nuclear magnetic resonance sensor 32 'is also located in the superposition field of the magnetic fields 34 and 36. Depending on the frequency of the irradiated electromagnetic field 36 and the static magnetic field strength of the first

Magnetic field 34, the sensitive region is defined in the ideal case by a surface on which the magnetic field strength of the first magnetic field 34 is constant and in particular has a defined amount. In reality, the surface is actually layered due to inaccurate frequencies. Since the magnetic field lines 34 do not run exactly parallel to the second housing side 40, the sensitive region 38 is therefore also curved in accordance with the magnetic field lines. The curvature and shape of the first magnetic field 34 and thus of the sensitive area 38 can be influenced and in particular homogenized using further means, for example a shim coil 56 and a magnetic shield 58.

FIG. 4b shows the components of an alternative embodiment of the nuclear magnetic resonance sensor 32 'according to the invention in a simplified and schematic representation. In this case, the first, in particular static, magnetic field 34 produced by the first device, here two parallel to the second housing side and collinearly arranged permanent magnets 46, 46 '(in north-south / north-south sequence), is essentially parallel to a second housing side 40 of the measuring device 10 and the second magnetic field generated by the second device, here a radio-frequency coil 48, 36 substantially perpendicular to the first magnetic field 34. Between the two permanent magnets 46,46 'is a high-frequency coil 48 whose winding plane is collinear to the extension direction of the permanent magnets 46,46' and parallel to the second side of the housing 40. This arrangement is positioned in close proximity to the second housing side 40. As soon as current flows through this coil, an electromagnetic field, in particular the second magnetic field 36, induced. The two magnetic fields overlap in a region which lies substantially outside the housing 12 of the measuring device 10. The sensitive region 38 of the nuclear magnetic resonance sensor 32 'is also located in the superimposition field of the magnetic fields 34 and 36. Depending on the frequency of the irradiated electromagnetic field 36 and the static magnetic field strength of the first magnetic field 34, the sensitive region is defined by an area on the ideal case the magnetic field strength of the first magnetic field 34 is constant and in particular has a defined amount. In reality, the surface is actually layered due to inaccurate frequencies. Since the magnetic field lines 34 do not run exactly parallel to the second housing side 40, the sensitive region 38 is therefore also curved in accordance with the magnetic field lines. The curvature and shape of the first magnetic field 34 and thus of the sensitive area 38 can be influenced and in particular homogenized using further means, for example a shim coil 56 and a magnetic shield 58.

FIG. 5 is a perspective, simplified representation of a plan view of the second housing side 40, i. the back of the hand-held meter 10, shown. On this second side of the housing 40, the receptacle of the energy storage device 22, in particular a battery or a rechargeable battery, under a housing flap (dashed) are directly accessible. A second housing flap 52, shown open in the figure, provides access to the radio frequency coil 48. Particularly advantageously, the connector plugs 50 of the radio frequency coil 48 are detachable, i. especially non-destructively separable executed. In this way, the high frequency coil 48 is allowed to be protected against high frequency coils having a different characteristic, i. which differ in particular with regard to their number of turns, type of winding, geometry and wire thickness, exchange. This possibility of varying the high-frequency coil 48 advantageously allows the second magnetic field 36 generated by the high-frequency coil 48 to be modified and, in particular, adapted and optimized to the conditions of the workpiece material. In this simplified representation, the other components of the nuclear magnetic resonance sensor 32 'of Figure 4a are not shown.

Claims

claims

1. Mobile measuring device, in particular hand-held measuring device, comprising a housing (12) in which at least

A sensor device (32),

A control device (28) for activating the sensor device,

An evaluation device (30) for evaluating measurement signals supplied by the sensor device (32),

such as

A device for power supply (22) of the measuring device are provided, characterized in that the sensor device (32) at least one nuclear magnetic resonance sensor (32 '), at least for determining a moisture value of a workpiece (42), in particular a moisture value in a Workpiece (42) is provided.

2. Measuring device according to claim 1, characterized in that an input device (14) for the input of working parameters is present, in particular in the housing (12) is present.

3. Measuring device according to claim 1 or 2, characterized in that an output device (16) for output of operating parameters and / or evaluation results is present, in particular in the housing (12) is present.

4. Measuring device according to claim 2 or 3, characterized in that the

Input device (14) and / or the output device (16) on a first side of the housing (20) is / are arranged.

5. Measuring device according to one of claims 1-4, characterized in that the nuclear magnetic resonance sensor (32 ') has a device for detecting a change in magnetic field (68), in particular a receiving coil for detecting a magnetic field change.

6. Measuring device according to one of claims 1-5, characterized in that the nuclear magnetic resonance sensor (32 ') a first device (46,46') for generating a first magnetic field (34), a second device (48), in particular a high-frequency coil, for generating a second, the first magnetic field (34) superimposed magnetic field (36), wherein the control device (28) at least one control unit for controlling the second device (48), wherein the control unit for modifying the second magnetic field (36), in particular for generating pulse sequences, is provided.

7. Measuring device according to claim 6, characterized in that the first magnetic field generated by the first device (46,46 ') of the nuclear magnetic resonance sensor (32') (34) substantially parallel to a second housing side (40) of the measuring device (10 ) and that the second magnetic field (36) generated by the second device (48) is oriented substantially perpendicular to the first magnetic field (34).

8. Measuring device according to one of claims 6-7, characterized in that the first device (46,46 ') for generating a first magnetic field (34) and / or the second device (48) for generating a second magnetic field (36) of at least one magnetic shield (58) is / are at least partially surrounded.

9. Measuring device according to one of claims 6-8, characterized in that the nuclear magnetic resonance sensor (32 ') at least one device for homogenization (56) of the first and / or second device (46,46' / 48) generated magnetic fields having.

10. Measuring device according to one of claims 6-9, characterized in that the second device (48) of the nuclear magnetic resonance sensor (32 ') for generating the second magnetic field (36), in particular the radio-frequency coil, is realized non-destructively interchangeable.

11. Measuring device according to one of claims 6-10, characterized in that the magnetic fields (34,36) of the nuclear magnetic resonance sensor (32 ') define a sensitive region (38) of the nuclear magnetic resonance sensor (32'), in particular a layered region extending substantially parallel and spaced from a second housing side (40) outside the housing (12) of the gauge (10).

12. Measuring device according to claim 11, characterized in that the sensitive region (38) of the nuclear magnetic resonance sensor (32 ') can be displaced along a vertical (66) to the second housing side (40) of the measuring device outside the housing (12), advantageous to 1 cm, particularly advantageous by 2 cm, in particular to move 3 cm.

13. Measuring device according to claim 11 or 12, characterized in that the second housing side (40) of the measuring device (10) of the input device (14) and / or the output device (16) receiving the first housing side (20) opposite, in particular device rear side is arranged ,

14. Measuring device according to one of claims 6-13, characterized in that the evaluation device (30) is designed for the evaluation of the sensor device (32) supplied measuring signals and in particular is provided, at least one amplitude and / or a relaxation time of a measuring signal, resulting from the excitation of nuclear spins in a workpiece (42) by the magnetic field (36) of the second device (48).

15. Measuring device according to claim 14, characterized in that the

Evaluation device (30) for evaluating provided by the sensor device (32) measuring signals is formed, by determining the number of lH atoms in the workpiece (42) at least

• a relative and / or absolute moisture content and / or

A moisture gradient into the workpiece 42 and / or

Bonding conditions of the moisture-forming water and / or

• temporal-dynamic processes of moisture forming water and / or

• to evaluate further structurally relevant parameters, in particular salinity, composition, density and / or porosity of the material of the workpiece (42), in particular to evaluate them with depth resolution.

16. A meter according to any one of claims 1-15, characterized in that a position determining device (24) for detecting at least one momentary position and / or orientation of the measuring device (10), in particular with respect to the workpiece (42), is provided.

17. Measuring device according to claim 16, characterized in that the

Evaluation device (30) for evaluating supplied by the sensor device (32) measuring signals is adapted to evaluate measurement signals of the sensor device (32) in dependence on the position and / or orientation of the measuring device (10), in particular based on the workpiece (42).

18. Measuring device according to one of claims 1-17, characterized in that at least one storage device (64) for storing measurement results and / or working parameters is provided.

19. Measuring device according to one of claims 1-18, characterized in that the control device (28) and / or the evaluation device (30) has a data communication interface (54) for, in particular wireless, communication, by means of which the measuring device (10) measurement results and / or send and / or receive working parameters.

20. Measuring device according to one of claims 1-19, characterized in that the control device (28) has an operating mode in which information on a workpiece (42) specified by user input and / or the measuring device (10) can be provided.

21. Measuring device according to one of claims 3-20, characterized in that the control device (28) has an operating mode in which output parameters of the output device (16) can be specified and / or the measuring device (10) can be provided.

22. Measuring device according to one of claims 1-21, characterized in that the sensor device (32) has at least one further sensor from a group of sensors which at least induction, capacitance, ultrasonic, temperature, humidity, radiation , tilt, angle, magnetic field, acceleration and rotational rate sensitive sensors includes.

23. Method for operating a measuring device (10), in particular method for operating a measuring device (10) for determining at least one moisture value of a workpiece (42), in particular a moisture value in a workpiece (42), in particular a method for operating a measuring device (10 ) according to any one of claims 1-22, characterized by at least the following steps:

i. Generating a first magnetic field (34) in the workpiece (42) by means of a first device (46, 46 ') arranged in the measuring device

ii. Generating high-frequency pulses (36) in the workpiece (42) by means of a second device (48) of the measuring device, in particular by means of a high-frequency coil

iii. Detecting at least one amplitude and / or a relaxation time of a measurement signal resulting from the excitation of nuclear spins in the workpiece (42), in particular by means of an electrical current induced in a receiver coil (68) and / or an induced voltage iv. Extraction of Larmor frequencies from a measuring signal, in particular from an electrical current and / or voltage v induced in a receiving coil (68). Evaluation of measurement signals of the nuclear magnetic resonance sensor (32 ') for determining a moisture value of the workpiece (42), in particular a moisture value in the workpiece (42), by means of an evaluation device (30) arranged in the measuring device.