• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The invention relates to a device for the impedance-based testing of materials, comprising a 2-dimensional array of coils (1) and a measuring unit (4), which are designed to determine a parameter for each coil (1), which of their impedance depends. A pulse generator (3) is capable of generating current pulses in each coil (1). The circuit drives the coil array and reads it out using row and column lines rp1 ... rpN1, cp1 ... cpN2, c21 ... csN2 to minimize the number of components required. The device can be used in particular for testing concrete.
    公开号:CH709376B1
    申请号:CH01018/15
    申请日:2013-01-14
    公开日:2016-09-15
    发明作者:Stierli Peter
    申请人:Proceq Sa；
    IPC主号:
    专利说明:

    Technical area
    The invention relates to a device for the electrical impedance testing of a material according to the preamble of claim 1, comprising at least one coil, a pulse generator for generating current pulses in the coil and a measuring unit for determining a parameter indicating the impedance of the coil.
    background
    It is known to test materials, such as reinforced concrete, by means of electrical impedance measurement devices. Such devices include a coil and a pulse generator to provide current pulses to the coil. After each current pulse, the magnetic field generated by the coil expires and generates a decaying induction voltage across the coil. The decay of this voltage is a function of the impedance of the coil, which depends on the permeability μ and the conductivity σ of the material within the range of the field. For example, if the coil is close to a metallic reinforcing rod embedded in the concrete, the average permeability μ and conductivity σ in the region of the field and thereby the impedance of the coil will change, resulting in a slower decay of the induction voltage.
    Therefore, by measuring a parameter indicating the inductance of the coil, it is possible to gain insight into the composition of the material adjacent to the coil. This is particularly useful for determining the location, depth and / or diameter of reinforcing bars or other metal parts in concrete.
    Presentation of the invention
    The problem to be solved by the present invention is to further improve this type of device. This problem is solved by the device according to claim 1. Accordingly, the device has a 2-dimensional array of coils. Further, the measuring unit is configured to determine a parameter indicating the impedance of individual coils of said coils. Such a design allows a spatially resolved measurement of the material, for example for locating the position and / or orientation of a reinforcing bar and / or other metal part in concrete.
    Further, the pulse generator is adapted to supply individual current pulses to each of the coils, that is, it is possible to supply a current pulse to each selected coil without supplying pulses to other coils. This allows a well-located magnetic field to be generated at any position within the array.
    Further, the measuring unit may be configured to measure the mentioned parameter, for example, for individual individuals of the mentioned coils.
    The coils can be advantageously formed by tracks on a printed circuit, which allows to produce them at low prices.
    The device is advantageously used for testing concrete, in particular for testing reinforced concrete, to locate reinforcing bars or other metal parts therein.
    Brief description of the drawings
    The invention will be better understood and other objects than those mentioned above will become apparent when the following detailed description is considered. This description refers to the attached figures, wherein:<Tb> FIG. 1 <SEP> shows a block diagram of the components of a device,<Tb> FIG. 2 <SEP> shows an embodiment of the coil circuit,<Tb> FIG. 3 <SEP> shows an embodiment of the most important components of the measuring unit,<Tb> FIG. 4 <SEP> shows the coils on a printed circuit and<Tb> FIG. Figure 5 is an illustration of a coil implemented on a multilayer printed circuit.
    Ways to carry out the invention
    definitions:
    The term "2-dimensional array of coils" is understood to mean that the coils are arranged in a matrix on a flat or curved plane, with a first number N1> 1 of coils side by side along a row direction and a second number N2> 1 of the coils are arranged side by side along a column direction, wherein the row and column directions extend transversely to one another.
    The term "device for an impedance-based testing of materials" is to be understood as a device for determining properties of a test material, such as concrete, by means of coils, which are brought into the vicinity of the material. Current pulses are passed through the coils and the build up or decay of the magnetic field of the coils is a function of permeability μ and conductivity σ, which are seen by the field, and which depends on the composition of the material. Thus, the device is designed to determine a property depending on the permeability μ, and / or conductivity σ of the material.
    Overview:
    Fig. 1 shows an overview of the components of a device according to the present invention. As can be seen, the device comprises a plurality of coils 1 arranged in a 2-dimensional array in rows and columns, as indicated by the row direction x and the column direction y. Although the number N1 of coils in each row may be the number N2 of coils in each column as low as 2, advantageously both of these numbers are greater than 2 in order to obtain spatially well-resolved information for the material under test. In the embodiment of Fig. 1, N1 = N2 = 6, but other numbers, such as 8 or 16, may also be used.
    A coil circuit 2 is associated with each coil 1. Furthermore, the device has a pulse generator 3, a measuring unit 4 and a control unit 5. Pulse generator 3 is designed to supply individual current pulses to each of the coils 1, while the measuring unit 4 is able to determine for each coil a parameter indicating its impedance. The control unit 5 coordinates the operation of the pulse generator 3 and the measuring unit 4. The configuration of these components will be described in more detail in the next sections.
    Pulse generator:
    Pulse generator 3 has row pulse lines rp1 ... prN1 and column pulse lines cp1 ... cpN2, all of which are connected to a timer circuit 6. In each cell i, j of the 2-dimensional array, a column pulse line cpi intersects with a row pulse line rpj. In operation, for example, one of the row pulse lines is set to a high potential (eg, 10 volts) while the others are kept at a low potential (such as 0 volts). Further, the column pulse lines are maintained at a high potential (such as 10 volts) with the exception of one to which at least one low potential pulse (for example, 0 volts) is applied.
    Coil circuits:
    As shown, the coil circuit 2 has a first input 10 connected to a column pulse line cpi, a second input 11 connected to a row pulse line rpj and an output connected to a column signal line csi on the assumption that i and j are the coordinates of the coil circuit in the 2-dimensional array of the coils.
    Further, each coil circuit 2 comprises a first semiconductor switch T1 and a second semiconductor switch T2, that is, a first semiconductor switch T1 and a second semiconductor switch T2 are associated with each coil 1. Both of these switches may be, for example, FETs or bipolar transistors. Each of them has two power terminals (such as the source and drain for a FET or the collector and emitter for a bipolar transistor) and a control terminal (such as the gate for a FET or the base for a bipolar transistor). As is known to those skilled in the art, the conductivity between the first and second power terminals is controlled by the voltage at the control terminal, allowing the current between the power terminals to be turned on or off by changing the voltage at the control terminal.
    As can be seen, one terminal of the coil 1 is connected to ground (or other fixed reference potential) while the other terminal of coil 1 (at point P) is connected to one of the power terminals of the semiconductor switch T1. The second power terminal of the semiconductor switch T1 is connected to the row pulse line rpj. The control terminal of the semiconductor switch T1 is connected to the column pulse line cpi.
    Further, the coil circuit 2, as mentioned, a second semiconductor switch T2, whose control terminal is connected to the row pulse line rpj, whose one power terminal is connected via a resistor R1 to the coil 1, and the second power terminal is connected to the column signal line csi. Resistor R1 has a resistance of 10-1000 Ω.
    Measuring unit:
    The embodiment of the measuring unit 4 is shown in Fig. 3. It comprises an analog demultiplexer 20 having N2 inputs connected to the column signal lines cs1 ... csN2 and an output 21. The semiconductor switches T3 allow each input to be selectively connected to the output 21. The control terminals of the semiconductor switches T3 are controlled by the control unit 5 and the pulse generator 3.
    The signal from the output 21 is applied to the inverting input of an operational amplifier 22, that is, demultiplexer is arranged between the column signal lines cs1 ... csN2 and the amplifier 22. The amplifier 22 has a resistor R2 in its feedback line. The non-inverting input of the amplifier 22 is connected to a constant reference potential Vref.
    In addition, and as can be seen, a voltage limiter 23, which has, for example, two reverse polarity, parallel Schottky diodes, at the input of the amplifier 22 is arranged. It limits the voltage at the input of the amplifier 22 to not more than 100 V to ground, in particular to less than 1 V, for example to a few 100 mV to ground.
    business
    The operation of the above embodiment of the apparatus will be described below.
    In normal operation, the control unit 5 operates the pulse generator 3 to generate a series of pulses on the row and column pulse lines rp1 ... rpN1 and cp1 ... cpN2, thereby activating individual coils 1 in the coil matrix.
    For example, to activate the coil in row j and column i, the pulse generator 3 sets all the row pulse lines except the row pulse line rpj to the low potential while the row pulse line rpj is set to the high potential. All column pulse lines cp1 ... cpN2 are set to high potential. Further, the demultiplexer 20 is set to connect only the second column pulse line csj to the output 21. In this state, all the semiconductor switches T1 are nonconductive, that is, no current flows through any of the coils 1. In addition, only the semiconductor switches T2 in row j are conductive, and the demultiplexer 20 only connects the coil in column i of row j to the input of the amplifier 22.
    Now, the pulse generator 3 applies a pulse with low potential to the column pulse line cpi, whereby it transfers the semiconductor switch T1 in its conducting state, so that a current through the coil 1 in line j and column i begins to flow. Once a sufficiently strong magnetic field is established, the column pulse line cpi is reset to its high potential, thereby breaking the semiconductor switch T1. This leads to the immediate construction of a negative induction splitting at the point P. The absolute value of this splitting can be more than 100V and easily exceed the maximum allowable voltage between the current terminals and the control terminal of the second semiconductor switches T2 and T3. However, since these semiconductor switches are in their conducting state and connected to the voltage limiter 23, the voltage limiter limits the voltage between the current terminals of the semiconductor switches T2 and T3 and their gates to an acceptable value. The voltage between the semiconductor switch T2 and point P drops across the resistor R1.
    Thus, the voltage limiter 23 protects the semiconductor switches T2 and T3 against excessive voltages. Another purpose of the voltage limiter 23 is to prevent the amplifier 22 from operating in saturation while the voltage across coil 1 is high, thereby making the amplifier operational as soon as its input voltage drops to lower values.
    After its initial peak, the induction voltage begins to decay, with a decay rate dependent on the impedance of coil 1. To measure an impedance dependent parameter, the output of amplifier 22 is sampled at a time when the voltage is at point P has dropped to a fairly low value so that the amplifier 22 is in its linear operating range. In this operating range, the gain of the amplifier 22 is given by the quotient R2 / R1 and is at least 5, in particular at least 10.
    The voltage at the output of the amplifier 22 is measured at a given time after the current is turned off by the coil 1 and is used to determine the response of the test material at the location of the cell i, j of the two-dimensional coil array.
    It should be noted that, alternatively to the use of the second semiconductor switch T2 and / or the demultiplexer 20, the output side (right side in Fig. 2) of the resistor R1 of all cells of a row, a column or in the whole matrix could be connected directly to the input of the amplifier 22. In this case, however, the amplifier noise of the amplifier 22 would be higher because of the lower impedance of its inverting input to ground.
    For this reason, it is advantageous to provide the second semiconductor switches T2 and / or the demultiplexer 20 between the coils 1 and the amplifier 22, so that the amplifier 22 can be connected such that it receives the induction voltage from a single coil 1 or at least of only a subset of the coils at a time.
    Mechanical design:
    The mechanical design of the device is shown in Figs. 4 and 5. As can be seen, the coils 1 are advantageously formed by the conductive tracks 34 on a printed circuit 30. They are arranged in columns and rows in a 2-dimensional array. They form N1 rows along the row direction x and N2 columns along the column direction y. As mentioned, N1 and N2 are advantageously greater than 2, for example 8, to achieve reasonable spatial resolution. The coil circuit 2 of each coil 1 may be disposed adjacent to its coil, even in a 2-dimensional array of the same number of rows and columns. Other switching elements, which are identified by the reference numerals 31, 32 and which comprise, for example, the pulse generator 3, the control unit 5 and / or the measuring unit 4, may for example be arranged on the edge of the printed circuit 30 or on a separate printed circuit.
    The printed circuit 30 is preferably a multilayer printed circuit, that is, it has a plurality of layers 33, as schematically illustrated in FIG. 5. As known to those skilled in the art, each such layer may carry its own metallic lanes. The coil 1 is advantageously formed by the conductive tracks 34 on a plurality of the layers 33. Each track 34 forms a spiral, all of the coils being of substantially similar design and wound about a common axis.
    Remarks:
    The device of Fig. 4 shows an embodiment in which the row and column directions x, y are perpendicular to each other. However, they can also be arranged at different angles, for example 60 ° or 120 °.
    In summary, for the impedance-based testing of materials, the present device has a 2-dimensional array of coils 1 and a measuring unit which are designed to determine for each coil 1 a parameter which depends on its impedance. The pulse generator 3 is capable of generating current pulses in each coil 1. The circuit drives the coil array and reads it out using row and column lines rp1 ... rpN1, cp1 ... cpN2, cs1 ... csN2 to minimize the number of components required. The device can be used in particular for testing concrete, but it can also be used in other applications.
    While presently preferred embodiments of the invention are shown and described, it is to be understood that the invention is not limited thereto, but that it may be otherwise practiced and practiced within the scope of the following claims.
    权利要求:
    Claims (11)
    [1]
    1. A device for an impedance-based examination of a material, characterized by a 2-dimensional array of coils (1) arranged in rows and columns, a pulse generator (3) for generating current pulses in the coils (1) and a measuring unit (4) for Determining a parameter of individual coils (1) which indicates the impedance of the coils (1),wherein the pulse generator (3) is adapted to supply individual current pulses to each of the coils (1), and wherein the pulse generator (3) comprises:Row pulse lines (rp1 ... rpN1), wherein one of the row pulse lines (rpj) is arranged along each row,Column pulse lines (cp1 ... cpN2), one of the column pulse lines (cpi) being arranged along each column,first semiconductor switch (T1), each coil (1) being associated with a first semiconductor switch (T1) and each first semiconductor switch (T1) having first and second power terminals and a control terminal, conductivity between the first and second power terminals is controlled by a voltage at the control terminal, the coils (1) and the row pulse lines (rp1 ... rpN1) are connected to the power terminals and the column pulse lines (cp1 ... cpN2) are connected to the control terminals.
    [2]
    2. Device according to claim 1, wherein the coils are arranged in a flat or curved plane, wherein a first number N1> 2 of the coils (1) along a row direction (x) and a second number N2> 2 of the coil (1) along a column direction (y) are arranged, wherein the row and column directions (x, y) extend transversely, in particular at right angles, to each other.
    [3]
    3. Device according to one of the preceding claims, further comprising second semiconductor switch (T2), wherein the measuring unit (4) comprises an amplifier (22), wherein each of the second semiconductor switch (T2) between one of the coils (1) and the amplifier ( 22) is arranged to connect a single or a subset of the coils (1) to the amplifier (22).
    [4]
    4. Apparatus according to claim 3, wherein each coil (1) is associated with a second semiconductor switch (T2).
    [5]
    5. Apparatus according to claim 4, further comprising column signal lines (cs1 ... csN2),wherein each second semiconductor switch (T2) has a first and a second power connection and a control connection, wherein a conductivity between the first and the second power connection is controlled by a voltage at the control connection, and wherein, for each second semiconductor switch (T2)the control terminal is connected to the row pulse line (rp1 ... rpN1) of the row of the coil (1) assigned to the respective semiconductor switch (T2),the first power connection is connected to the respective semiconductor switch (T2) associated coil (1) andthe second power connection is connected to one of the column signal lines (cs1 ... csN2).
    [6]
    6. The device of claim 5, further comprising a resistor (R1) disposed between the first power terminal of the second semiconductor switch (T2) and the coil (1), and in particular wherein the resistor has a resistance of 10-1000 Ω.
    [7]
    A device according to any one of claims 5 or 6, comprising a demultiplexer (20) between the column signal lines (cs1 ... csN2) and the amplifier (22), which is adapted to receive a single one of the column signal lines (cs1 ... csN2 ) to the amplifier (22).
    [8]
    Apparatus according to any of claims 4 to 7, further comprising a voltage limiter (23) disposed at an input of the amplifier (22) and configured to provide a voltage at said input at a maximum allowable voltage between the power terminals and the control terminal of second semiconductor switch (T2), and in particular wherein the maximum allowable voltage is less than 100V.
    [9]
    9. Device according to one of the preceding claims, wherein the coils (1) of conductive tracks (34) on a printed circuit (30) are formed.
    [10]
    Apparatus according to claim 9, wherein the printed circuit (30) comprises a plurality of layers (33), each coil (1) being formed by conductive traces on a plurality of said layers (33).
    [11]
    11. Use of the device according to one of claims 1 to 10 for testing concrete, in particular reinforced concrete.
    类似技术:
    公开号 | 公开日 | 专利标题
    DE112013006418T5|2015-10-15|Impedance-based measuring device with a 2-dimensional array of coils
    DE2529475C3|1981-10-08|Electrical circuit arrangement for time-dependent measurement of physical quantities
    WO2004051853A2|2004-06-17|Magnetic logic device
    EP1141960B1|2002-07-03|Read/write architecture for a mram
    EP0285961A1|1988-10-12|Infrared detector
    EP1462770A2|2004-09-29|Offset compensated Hall-sensor
    DE102011054147B4|2017-07-27|Test device and test method
    DE1954939A1|1970-05-14|Storage matrix
    DE3008754C2|1989-01-19|
    DE1774459A1|1971-12-16|Memory circuit
    DE10303409A1|2004-09-09|Method and circuit arrangement for determining an electrical measured value for a resistance element, preferably for determining an electrical current through the resistance element
    DE1474457B2|1972-01-20|MEMORY WITH AT LEAST ONE BINARY STORAGE ELEMENT IN THE FORM OF A BISTABLE CIRCUIT
    DE2120910A1|1971-11-18|Arrangement for generating electrical signals dependent on the coordinates in a plane
    CH621657A5|1981-02-13|
    EP1450167A1|2004-08-25|Method and device for measuring the resistance of an electronic component
    DE1186509B|1965-02-04|Magnetic memory with a magnetic core provided with holes perpendicular to each other
    DE102010048917B4|2016-12-01|Eddy current sensor surface
    DE1774813B1|1972-01-20|MEMORY ELEMENT WITH TRANSISTORS AND MATRIX MEMORY WITH THESE STORAGE ELEMENTS
    DE10308029B3|2004-10-28|Electrical component resistance value determination method e.g. for current measuring shunt resistance, using measuring bridge containing reference resistance in series with component and known resistances
    DE1499853A1|1970-04-09|Cryoelectric storage
    DE1283279B|1968-11-21|Magnetic information storage device
    DE1268676B|1968-05-22|Magnetic core memory
    DE1524001B2|1974-06-20|Test circuit for a selection circuit
    DE2219054C3|1974-01-17|Strain gauge arrangement for converting mechanical stresses into corresponding binary coded electrical quantities
    DE190821C|
    同族专利:
    公开号 | 公开日
    DE112013006418T5|2015-10-15|
    CN104969062A|2015-10-07|
    US20150355121A1|2015-12-10|
    US9804111B2|2017-10-31|
    CN104969062B|2018-01-19|
    WO2014107816A1|2014-07-17|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    CH669843A5|1985-08-27|1989-04-14|Proceq Sa|Diameter measuring apparatus for rods embedded in concrete - has moving inductive probe and evaluating circuit with memory and comparison system|
    CN1011549B|1988-03-17|1991-02-06|广西师范大学|Automatic iron analyzing system|
    EP0399026A1|1988-12-08|1990-11-28|Protovale Limited|Instrument for measuring reinforcing bars|
    US6720775B2|2001-06-12|2004-04-13|General Electric Company|Pulsed eddy current two-dimensional sensor array inspection probe and system|
    US6819121B1|2002-10-23|2004-11-16|Material Sensing & Instrumentation, Inc.|Method and apparatus for measurement of concrete cure status|
    JP4710061B2|2005-02-04|2011-06-29|株式会社竹中工務店|Concrete component measuring apparatus and measuring method|
    WO2007056679A2|2005-11-03|2007-05-18|The Clock Spring Company L.P.|Comformable eddy current array|
    WO2007098190A2|2006-02-21|2007-08-30|Beth Israel Deaconess Medical Center, Inc.|Magnetic resonance imaging and radio frequency impedance mapping methods and apparatus|
    DE102006060417B4|2006-12-20|2008-09-11|Siemens Ag|System for generating a voltage pulse with a pulse generator, method of control and their use|
    WO2009044233A1|2007-10-04|2009-04-09|Freescale Semiconductor, Inc.|Microprocessor, system for controlling a device and apparatus|
    CN101246116A|2008-03-31|2008-08-20|南京航空航天大学|Concrete reinforcement erosion wireless detecting method and sensor|
    DE102008051802A1|2008-10-17|2010-04-29|Sgl Carbon Ag|Method for measuring the wear of carbon ceramic friction plates and device therefor|
    DE102008056416B4|2008-11-07|2018-08-30|Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.|Eddy current sensor array for non-destructive position detection of electrically conductive objects|
    CA2727513A1|2010-01-06|2011-07-06|Russell Nde Systems Inc.|Blanket probe|
    FR2965356A1|2010-09-23|2012-03-30|Airbus Operations Sas|NON-DESTRUCTIVE CONTROL OF A STRUCTURE IN AN AIRCRAFT|
    US8754625B2|2010-09-30|2014-06-17|Intersil Americas Inc.|System and method for converting an AC input voltage to regulated output current|
    US8569963B2|2011-06-17|2013-10-29|Intersil Americas Inc.|Cascade boost and inverting buck converter with independent control|
    DE102011088169A1|2011-12-09|2013-06-13|Robert Bosch Gmbh|Voltage converter for a motor vehicle|EP3586128A1|2017-03-10|2020-01-01|Proceq SA|Probing a structure of concrete by means of electromagnetic waves|
    EP3612824A1|2017-06-20|2020-02-26|Proceq SA|Inductive characterization of a metal object embedded in concrete and related detection device|
    US11046193B2|2018-01-23|2021-06-29|Witricity Corporation|Foreign object detection circuit using current measurement|
    JP6879969B2|2018-03-19|2021-06-02|三菱重工業株式会社|Eddy current flaw detection probe|
    DE102018222660A1|2018-12-20|2020-06-25|Micro-Epsilon Messtechnik Gmbh & Co. Kg|Method for detecting defects or changes in length on a needle-shaped measurement object, device for using the method and printed circuit board as part of the device|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    PCT/CH2013/000008|WO2014107816A1|2013-01-14|2013-01-14|Impedance-based measurement device with a two-dimensional array of coils|
    [返回顶部]