Apparatus and method for detecting uncoated areas in a liner.

Abstract

This invention provides a method and device for detecting uncoated areas (holes) in electrical insulating materials. [Solution] An apparatus and method for identifying liner unpainted areas, comprising a generator having two contacts with the liner and a moving contact of one of the contacts that pulses current, wherein a plurality of detected electrical signals are processed to successively generate baselines indicating unpainted areas. Unpainted areas signals are activated when signals indicating unpainted areas are detected when compared to the generated baselines. Multiple electrical signal types and baselines, such as current intensity and voltage, may be detected individually in the unpainted areas signals, which are activated when signals indicating unpainted areas are detected when compared to the generated baselines. The moving contact may be flexible to follow the contour of the liner.

Description

Technical Field

[0001] Cross - Reference to Related Applications Not applicable.

[0002] Federally Sponsored Research or Development Not applicable.

[0003] Microfiche / Copyright Reference Not applicable.

[0004] Method and device for detecting overspray (holes) in electrical insulators.

Background Art

[0005] Conventional overspray or hole detection uses a device that includes a high - voltage source connected to a plurality of electrodes located on the surface of an insulating layer. One electrode is swept along the surface being inspected, and when it encounters overspray in the insulating layer, a spark jumps from the electrode into the hole. The detection mechanism identifies any spark event and typically sends a signal to an operator (e.g., by an audible sound and / or a visual indication). Then the operator can notice that the position of the electrode is the position of the overspray.

[0006] The high - voltage source was either direct current (DC) or alternating current (AC), but usually the voltage was pulsed (AC) such that each pulse reached a maximum voltage during a short time interval. The high - voltage source was usually pulsed at a rate fast enough to ensure that the inspection area was included while the electrode was being pulled or pushed by the user. Particularly in the case of AC pulses, the detection mechanism must be able to reliably distinguish a normal pulse discharge (no overspray) from a spark (overspray), and such a distinction has typically been based on changes in the current or voltage amplitude sensed during the absence and presence of a spark.

[0007] Unfortunately, conventional detection mechanisms have often struggled to reliably detect unpainted areas. These mechanisms operate on inductive coupling, sensitive to changes in current flowing through the cable from the pulse generator to the brush (with respect to time), but not to changes in charge. Unpainted areas cause transients in the current and charge generated around the electrode. Since the current in the cable is proportional to the impedance between the brush and the liner, when an unpainted area is encountered, the impedance changes instantly, and the amplitude of the perceived current reflects this change. Such detection mechanisms determine whether the peak current amplitude exceeds a threshold indicating an unpainted area, and when the threshold is exceeded, they generate an audible and / or visual indication to show that the electrode is located in an unpainted area.

[0008] However, similar current changes can arise from impedance changes caused by reasons other than sparks, and such impedance changes may be indistinguishable from those resulting from missed spots. For example, when electrodes are swept across an insulating surface, there are instantaneous fluctuations in the current or voltage distributed to the electrodes, and these normal fluctuations have often been flagged as missed spots, even when there are no sparks or holes in the insulating surface or liner. In addition, changes in the earth conductivity of the soil beneath the liner can cause fluctuations that mislead the detection mechanism, producing false positives (incorrect indications of sparks / holes).

[0009] Conventional paintless paint detectors have allowed users / operators to manually adjust the sensitivity level (i.e., the peak current amplitude threshold chosen to indicate a spark) to minimize false positives. However, such adjustments do not fully address false positives and false negatives. That is, while the threshold can be manually adjusted, such adjustments are only approximations of a suitable threshold across the area. Therefore, the threshold may be adjusted to ensure that the detector is sensitive enough to give a positive signal where paintless paint is known to be present, but not sensitive enough to give a positive signal where paintless paint is not known to be present, but such a threshold may not be appropriate in other areas of the liner where different conditions exist (e.g., different ground detectability, changes in brush contact). In short, when detecting paintless paint in a liner, a threshold selection that works well across one area of ​​the liner may not be suitable for other areas, resulting in missed paintless paint and / or indicating paintless paint when it does not exist.

[0010] The apparatus and methods disclosed herein significantly overcome the aforementioned disadvantages of the prior art. [Overview of the Initiative]

[0011] A method and apparatus for detecting uncoated areas on an electrical insulating surface are disclosed herein. The apparatus is a portable device comprising a high-voltage generator, at least two moving electrodes for delivering charge to a liner, and a detection mechanism having the ability to identify uncoated areas under a wide range of variable environmental or operating conditions due to electrode motion, variable soil resistivity, or other factors. The uncoated area detector uses smart signal processing to accurately indicate uncoated areas with minimal environmental variability, without the need for manual adjustment.

[0012] One aspect of the present disclosure is a method for detecting unpainted areas in a liner, comprising the steps of: (a) creating a circuit for current from a generator to a first contact of a liner having a liner to a second contact spaced apart from a first contact of a generator, the second contact being an electrical reference of the generator; (b) pulsing a current from the generator to the first contact of the liner as the first contact is moved over the liner; (c) detecting a plurality of at least one electrical signals relating to the pulsed current from the electrical reference; (d) processing a selection of the most recent plurality of detected electrical signals in sequence to generate a baseline value of at least one electrical signal, wherein a detected electrical signal having a value on one side of the baseline is deemed to indicate no unpainted areas, and an electrical signal having a value on the other side of the baseline is deemed to indicate unpainted areas; and (e) activating an unpainted signal when at least one of the detected electrical signals has a value on the other side of the baseline.

[0013] In one form of this embodiment of the present disclosure, the second contact point is at the top of the liner. In one alternative form, the second contact point is at the ground below the liner.

[0014] In one form of this embodiment of the present disclosure, the liner has a top surface and a conductive bottom surface, and the first and second contacts are in contact with the top surface of the liner. In a further form, the liner is a geomembrane for geotechnical use on the ground. In yet another form, the geomembrane includes a plurality of liners connected by joints.

[0015] In another form of this aspect of the present disclosure, at least one electrical signal is a selected one of current intensity and voltage.

[0016] In yet another form of this aspect of the present disclosure, at least one electrical signal includes both current intensity and voltage, wherein the detected current intensity is processed sequentially to generate a baseline of current intensity, and the detected voltage is processed sequentially to generate a baseline of voltage. In yet another form, an unfilled signal is generated when either the current intensity or the voltage passes its generated baseline.

[0017] In yet another form of this aspect of the present disclosure, at least one of energy averaging, filtering, and Fourier spectroscopy is used to generate a baseline from a plurality of recent detected electrical signals.

[0018] Another form of this aspect of the present disclosure includes a baseline which is a selected value greater than the average of the most recent multiple detected electrical signals.

[0019] Another form of this aspect of the present disclosure includes the activated unpainted signal being at least one of an audible sound and an alarm light.

[0020] A further form of this aspect of the present disclosure includes a position indicator corresponding to an area of ​​the liner that is in contact with the first contact when the detected electrical signal indicates a value on the other side of the baseline. In a further form, the activated unpainted signal is at least one of a grid coordinate signal on the liner, an audio signal, a visual signal, and a GPS coordinate signal.

[0021] In another aspect of the present disclosure, a sensor for detecting unpainted areas in a liner includes a pulsing generator having an electrical reference, electrodes made to move and maintain on contact with the liner spaced apart from the generator electrical reference while the generator pulses a current to the electrodes, a processor, and an unpainted signal activated when any detected electrical signal has a value on the other side of a baseline. The processor is made to detect at least one electrical signal associated with a pulsed current over time from the generator electrical reference, process at least one electrical signal detected during a selected period sequentially over the most recent selected period, and generate a baseline of at least one electrical signal, wherein a detected electrical signal having a value on one side of the baseline is deemed to indicate no unpainted areas, and an electrical signal having a value on the other side of the baseline is deemed to indicate unpainted areas.

[0022] In one form of this aspect of the present disclosure, the electrical reference is positionable in the liner.

[0023] In another form of this aspect of the present disclosure, the processor is configured to detect one of a selected current intensity and voltage.

[0024] In another form of this aspect of the present disclosure, the processor is configured to detect both current intensity and voltage, to process the current intensity sequentially to generate a current intensity baseline, and to process the voltage sequentially to generate a voltage baseline. In yet another form, the unpainted signal is activated when either the detected current intensity or the detected voltage is on the other side of the baseline generated therefrom.

[0025] In yet another form of this aspect of the present disclosure, the processor is configured to generate a baseline from a plurality of recent detected electrical signals using at least one of energy averaging, filtering, and Fourier spectroscopy.

[0026] In yet another form of this aspect of the present disclosure, the residual coating signal to be actuated is at least one of an audible sound and an alarm light.

[0027] In yet another form of this aspect of the present disclosure, the residual coating signal is a position indication corresponding to an area of the liner in contact with the electrode when the detected electrical signal value is on the other side of the baseline.

[0028] In yet another aspect of the present disclosure, a method of detecting residual coating in a liner includes: (a) creating a circuit for current from a generator to a first contact of the liner to a second contact spaced from the first contact to the generator, the second contact being the electrical reference of the generator; (b) sending current from the generator to the first contact of the liner when the first contact is moved across the liner; (c) detecting the current intensity and voltage at the generator electrical reference; (d) comparing the current intensity at the generator electrical reference with a baseline current intensity; (e) comparing the voltage at the generator electrical reference with a baseline voltage; and (f) actuating a residual coating signal that is actuated when either the current intensity or the voltage has a value on one side of the baseline that is considered to indicate residual coating.

[0029] In one form of this aspect of the present disclosure, the liner has a top surface and a conductive bottom surface, and the first and second contacts are in contact with the top surface of the liner. In a further form, the liner is a geomembrane on a geotechnical site. In yet a further form, the geomembrane includes a plurality of liners connected at seams.

[0030] In another form of this aspect of the present disclosure, the detected current intensity is continuously processed to generate a baseline of the current intensity, and the detected voltage is continuously processed to generate a baseline of the voltage. In a further form, a residual coating signal is generated when either the current intensity or the voltage passes through the generated baseline.

[0031] In yet another form of this aspect of the present disclosure, at least one of energy averaging, filtering, and Fourier spectroscopy is used to generate a baseline from a plurality of recent detected electrical signals.

[0032] In yet another form of this aspect of the present disclosure, the baseline is a selected average of the most recent multiple detected electrical signals.

[0033] Another form of this aspect of the present disclosure includes the activated unpainted signal being at least one of an audible sound and an alarm light.

[0034] A further form of this aspect of the present disclosure includes a position indicator corresponding to an area of ​​the liner in contact with the first contact at a time when the current intensity has a value on one side of a current intensity baseline which is considered to indicate an unpainted area, or when the voltage has a value on one side of a voltage baseline which is considered to indicate an unpainted area.

[0035] In yet another aspect of the present invention, a sensor for detecting unpainted areas in a liner includes a generator having a positionable or adjacent electrical reference relative to the liner; an electrode spaced apart from the generator electrical reference and configured to move on the liner and maintain contact while the generator delivers current to the electrode; a detector for detecting current intensity and voltage at the generator electrical reference; and a processor configured to (i) compare the current intensity at the generator electrical reference with a baseline current intensity, and (ii) compare the voltage at the generator electrical reference with a baseline voltage. An unpainted signal is activated when the detected current intensity has a value on the side of the baseline current intensity which is considered to indicate an unpainted area, or when the detected voltage has a value on the side of the baseline voltage which is considered to indicate an unpainted area.

[0036] In one aspect of this disclosure, the processor is configured to process current intensities sequentially to generate a baseline current intensity and to process voltages sequentially to generate a baseline voltage. In a further aspect, the processor is configured to generate a baseline from a plurality of recent detected electrical signals using at least one of energy averaging, filtering, and Fourier spectroscopy.

[0037] In another form of this aspect of the present disclosure, an unpainted signal is activated when the detected current intensity or detected voltage is on the side of its generated baseline which is considered to indicate an unpainted area.

[0038] In yet another form of this aspect of the present disclosure, the unpainted signal to be activated is at least one of an audible sound and an alarm light.

[0039] In yet another form of this aspect of the present disclosure, the unpainted signal is a positional indication of an area of ​​the liner in contact with an electrode when the detector detects that at least one of the current intensity and voltage has a value on its baseline side which is considered to indicate an unpainted area.

[0040] Another aspect of the present disclosure is a sensor that defines a circuit for detecting unpainted areas in a liner having a changing contour, including a generator having an electrical reference and a contact that receives current from the generator. The contact is configured to move over an area of ​​the liner spaced apart from the generator electrical reference while the generator sends current to the contact, and the contact follows the changing contour of the liner area.

[0041] In one form of this embodiment of the present disclosure, the contact is a flexible conductive sheet.

[0042] In another form of this aspect of the present invention, the contact is a flexible chainmail.

[0043] In yet another form of this aspect of the present invention, the contact includes a trolley rolling on a guide wheel, a flexible conductive cable supported between the guide wheels, and a plurality of conductive rollers spaced apart along the cable, where each roller is rotatable around the cable.

[0044] Other objects, features, and advantages of the present invention will become apparent from a review of the entire specification, including the appended claims and drawings. [Brief explanation of the drawing]

[0045] [Figure 1] This is a schematic diagram of a prior art sensor used to detect uncoated areas in a liner. [Figure 2] Figure 1 is a schematic diagram of a prior art sensor and the electrode brush used in it. [Figure 3] Figure 1 is a schematic cross-sectional view of a grounding pad and liner placed on soil, as used in prior art liners and sensors. [Figure 4] This is a schematic diagram of a novel sensor disclosed herein, used for detecting uncoated areas in a liner. [Figure 5] This is a schematic diagram of a new movable contact of the sensor used to detect unpainted areas on the liner. [Figure 6A] This is a movable contact, an alternative to a sensor, used to detect unpainted areas on the liner. [Figure 6B] This is a movable contact, an alternative to a sensor, used to detect unpainted areas on the liner. [Figure 7] Figure 4 is a schematic diagram of an electromagnetic detector that may be used with the sensor shown. [Figure 8] This is a schematic diagram of an alternative embodiment of a paint-in-area sensor, in which both current and voltage can be detected to determine the presence of unpainted areas. [Figure 9] Sample waveforms of detected currents are shown, comparing the threshold values ​​used in prior art sensors with those determined by the novel sensor disclosed herein. [Figure 10] This flowchart illustrates the operation of a novel sensor, such as the one disclosed herein, which measures both current and voltage amplitudes and uses such measured amplitudes to dynamically determine thresholds for indicating the presence of unpainted areas, respectively. [Modes for carrying out the invention]

[0046] A novel apparatus and method for identifying liner uncoated areas, including a generator, is disclosed, as will be described in detail later. The generator has two contacts with the liner and sends a pulsed current to one of the contacts, a moving contact. The pulsed current is processed sequentially to continuously generate baselines indicating uncoated areas. In addition, multiple detected electrical signals, such as current intensities and voltages, may be processed in this way to continuously generate baselines for each signal indicating an uncoated area, and the uncoated signal is activated when any signal indicating an uncoated area is detected by comparing it with its generated baseline. The moving contact may be flexible to follow the contour of the liner.

[0047] As further background to this disclosure, Figures 1-3 herein provide further details regarding prior art apparatuses that improve upon the apparatuses and methods disclosed herein.

[0048] Specifically, Figure 1 shows a detection device defining the circuit, where the high-voltage generator 10 has a first cable 12 connected to an electrode or grounding pad 14 and a second cable 16 connected to a movable electrode or conductive brush 20. During use, the device grounding pad 14 (i.e., an electrical reference, e.g., the ground) is connected to the top of the liner 24 being inspected, and the electrode brush 20 is moved over an area of ​​the liner 24. The generator 10 provides a constant current or, in some versions, generates high-voltage pulses.

[0049] The grounding pad 14 functions as a capacitive plate for coupling electrical energy to the liner 24. However, it should be understood that in some applications, the grounding pad 14 may be placed on the ground rather than on the liner 24 (i.e., the grounding pad 14 may be placed on the ground or land outside the boundary of the liner 24).

[0050] The brush 20 is typically made of metal bristles 22 that form electrodes for distributing a high voltage onto the liner 24, where sparks are generated in the presence of uncoated areas. A non-conductive handle 26 is attached to the brush 20, allowing the user to sweep across the liner 24 with the brush 20 for inspection. However, as shown in Figure 2, the bristles of the brush 20 were susceptible to variations when in contact with the liner 24, especially when the liner contour was not flat.

[0051] As shown in Figure 3, the liner 24, such as a geomembrane, is typically laid on the soil 28 and is intended to be impermeable to the insulating top layer 30 and the conductive bottom layer 32. The device's circuitry will flow from the brush 20 through the liner 24 to the grounding pad 14. Such current flow will be affected if the brush 20 is in contact with an area of ​​the liner 24 that has a gap. That is, it should be understood that the current may flow through the gap and then along the conductive bottom layer 32, rather than being limited to flowing along the insulating top layer 30.

[0052] Such prior art devices included a detector 40 in the circuit for detecting current flow and a comparator 42 for comparing the signal with a threshold which is interpreted as indicating an uncoated area. For example, if the current intensity suddenly increases to a value exceeding the threshold, it would be interpreted as indicating an uncoated area (i.e., the sudden increase in intensity indicates a flow through the conductive bottom layer of the liner). However, as mentioned above, while a sudden increase in current flow may indicate an uncoated area, it can also result from other factors, such as instantaneous fluctuations in the current or voltage distributed to the electrodes and changes in the earth conductivity in the soil beneath the liner (e.g., depending on soil type and moisture). Other factors may include, for example, sudden changes in the motion of the brush 20 and / or sudden changes in the degree of contact between the brush 20 and the liner 24.

[0053] The thresholds used by comparator 42 were manually set based on operator experience or by first inspecting the current intensity in areas where no unpainted areas were known and / or where one unpainted area was known. After the inspection began, the thresholds were set for the entire area being inspected, however, the operator may manually change the thresholds if it was determined that the thresholds were incorrectly returning false positives (indicating no unpainted areas) or false negatives (failure to recognize existing unpainted areas).

[0054] When the detected electrical signal exceeded a threshold indicating that brush 20 was located in an unpainted area, the audible alarm 44 alerted the operator.

[0055] The improved apparatus and methods disclosed herein are shown beginning with Figure 4. Specifically, as shown in Figure 4 and described in more detail later, the sensor 100 for identifying uncoated areas of the liner 124 includes an improved movable electrode or contact 120 that maintains uniform contact with the liner 124 having an uneven contour. Furthermore, as also shown and described in more detail later, a high-voltage generator 110 generates a signal that is favorably processed by the sensor 100 in such a manner that false positives and false negatives are greatly reduced.

[0056] Specifically, as shown in Figures 4-5, the movable contact 120 includes a trolley 130 that rolls on guide wheels 132, having a flexible conductive cable 134 supported between the guide wheels 132. Multiple conductive rollers 136 are spaced apart along the cable 134, and each roller 136 is rotatable around the cable 134. As shown, if the cable 134 is flexible, all rollers 136 will be in contact with the liner 124 even in areas with undulating contours rather than flat ones.

[0057] Further variations of the movable contact include flexible, surface-conforming conductive materials, such as the chainmail 120A shown in Figure 6A, and a flexible conductive film 120B (e.g., conductive neoprene) shown in Figure 6B, which can be dragged across the liner 124.

[0058] Furthermore, referring to Figure 4 and the improvements disclosed herein, the sensor 100 also includes an unpainted area detector unit 150 which includes a high-voltage generator 110. The high-voltage generator may also be a high-voltage pulse generator 110A (see Figure 7), thereby allowing the unpainted area detector unit 150A to dynamically and advantageously determine the unpainted area baseline measurement, as will be described in more detail later.

[0059] Referring here to Figure 8, in another aspect of the present disclosure, the detector unit 150 may favorably include an electromagnetic detector 152 (see Figure 7), which senses not only the current transmitted through the high-voltage cable 116 but also the energy (voltage and current) from the high-voltage generator 110. The electromagnetic detector 152 is more sensitive than the current detectors used in prior art systems and is therefore less susceptible to false positive and false negative signals.

[0060] Furthermore, an electromagnetic detector 152, as shown in Figure 8, can be advantageously used in conjunction with the high-voltage pulse generator 110A. The electromagnetic detector 152 is a combination of a magnetic (inductive) coupler 154 and an electrical (capacitive) coupler 156 that senses energy fluctuations occurring in the high-voltage pulse generator 110A. The electromagnetic detector 152 is sensitive to changes in current flowing in the high-voltage cable 116 and changes in charge between the electrodes (e.g., Figures 5, 6A, 6B) and the liner 124. The processor 160 compares the sensed signals with thresholds (e.g., current and voltage) for each signal that indicates or is not considered to be unpainted.

[0061] (Generally, a sudden surge in a signal, such as a spark, that causes the current intensity to exceed a threshold or baseline would indicate a missed spot. However, it should be understood that for different signals, a signal decreasing below a threshold can also indicate a missed spot. For this reason, this disclosure generally, and sometimes here, refers to detecting a missed spot by exceeding or surpassing a baseline or threshold, but more precisely, when referring to a signal that indicates a missed spot based on that baseline or threshold, it should be said that a missed spot is detected when the signal intensity is on the side of [i.e., above or below] that baseline or threshold that is considered to indicate a missed spot.)

[0062] Furthermore, the electromagnetic detector 152 can advantageously measure changes in both current and voltage by coupling the high-voltage cable 116 via the winding and toroid 162 of the inductive coupler 154 and via the conductive plate 164 of the electrical (capacitive) coupler 156. Figure 8 shows sensor 100, in which an inductive coupler 154 with a toroid having winding 162 is used to sense the current in the high-voltage cable 116, and an electrical coupling 156 with a conductive plate 164 is used to sense the voltage. By detecting changes over time in both current (by measuring the magnetic field) and electric field, sensor 100 can detect smaller fluctuations than prior art sensors and is more sensitive to small misses. For example, each of multiple signals is compared to its own separate baseline, and a miss can be detected in cases where only one of the signals exceeds its baseline (for example, in cases where the miss may cause only a small change in current but a significant and noticeable change in electric field).

[0063] Therefore, it should be recognized that the disclosed sensor 100, which measures multiple signals (for example, current and voltage, not just current), can favorably minimize false positives and false positive signals.

[0064] A further advantageous feature of the disclosed sensor 100 is the dynamic determination of the threshold of the monitored signal, which is calculated sequentially by the processor 160. In this regard, the sensor 100 includes a high-voltage pulse generator 110A, and a smear detector unit 150 detects over time at least one of a plurality of electrical signals related to pulsed currents. The processor 160 sequentially processes each of the plurality of signal types (e.g., current or voltage) detected for the most recent selected period (e.g., 30 pulses per second per second), and sequentially generates and updates a dynamic baseline or threshold for each detected signal type. Such a baseline may be determined using the signal for the most recent selected period by a suitable method, e.g., energy averaging, filtering, and Fourier spectroscopy.

[0065] Figure 9 illustrates this feature in comparison to prior art sensors where the threshold is manually adjustable or fixed. In the illustrated example, the prior art fixed threshold is a flat line 180, while the dynamic, self-adjusting threshold 182 will vary depending on the given environmental changes encountered by the movable contact 120 (e.g., different soil resistivity in the area of ​​the movable contact 120 and / or in the movement of the movable contact 120). Thus, although the peak 186 may occur as a result of environmental factors within the area of ​​the movable contact 120 rather than an unpainted area, in the prior art, a peak 186 exceeding the prior art flat line threshold 180 would be interpreted as (incorrectly) indicating an unpainted area at the location of the movable contact 120. In contrast, in the sensor 100 disclosed herein, the processor 160 dynamically incorporates such environmental factors and creates an automatically correcting dynamic threshold 182 so that the comparison of the signal with the threshold takes environmental factors into account and avoids false positive signals. Similarly, if environmental factors would cause a reduction in the signal, the processor 160 disclosed herein would result in a reduced threshold (or threshold dip) and avoid false negative signals.

[0066] Figure 10 is a flowchart illustrating the operation of the sensor 100 disclosed herein, which has both dynamic threshold determination and detection of multiple different signals.

[0067] Specifically, the sensor 100 is first turned on (step 200), and the high-voltage pulse generator 110A is charged (step 202). The high-voltage pulse is discharged to the movable contact 120 via the high-voltage cable 116 (step 204), and the electromagnetic detector 150A of the unpainted area detection unit 150 acquires the current and voltage amplitude of the pulse (step 206), which the processor 160 uses to calculate the average signal strength indicating an unpainted area (step 208). In step 210, the processor 160 uses the calculated signal strength from step 208 to calculate a detection threshold for the generator 110 relative to an electrical reference (e.g., ground 14). The high-voltage pulse generator 110A is charged again (step 212), and the pulse is discharged to the movable contact 120 (step 214), and the electromagnetic detector 150A of the unpainted area detection unit 150 acquires the current and voltage amplitude of the pulse (step 216). This process of repeatedly discharging high-voltage pulses detected by the electromagnetic detector 150A and used by the processor 160 to update the dynamic threshold is repeated many times until a determined amount of pulse data is acquired, and as another pulse is added to the data, the data of the oldest pulse is excluded from the average calculated in step 208. The operation continues in this manner until the processor 160 determines that the pulse has exceeded the current calculated detection threshold (e.g., current and / or voltage amplitude), in which case an alarm or position indicator 144 is sent.

[0068] Sensor 100 conveniently allows the operator to control the aforementioned high-voltage pulsing by pressing an appropriate trigger switch when such pulsing is desired (first in step 200, and later in step 212 when sufficient data has been acquired).

[0069] The position indicator 144 may be a conventional audible alarm included in the unpainted area detector unit 150 that sounds when an unpainted area is detected (a sound that thereby warns the operator if an unpainted area is located at the position of the movable contact 120), and / or may include any suitable signal, including a visual signal (e.g., light) or a digital signal that marks the position of the movable contact 120 (and thus the unpainted area) on the grid.

[0070] A review of the aforementioned disclosures should lead to the understanding that detection of uncoated areas in a liner (e.g., a geomembrane) can be advantageously, easily, and reliably achieved with minimal false positive and / or false negative indications.

Claims

1. A method for detecting uncoated areas in a liner, A step of creating a circuit for current from the generator to the first contact and the liner to the second contact spaced apart from the first contact to the generator, wherein the second contact is the electrical reference of the generator, The steps of pulsing the current from the generator to the first contact of the liner as the first contact moves along the liner, A step of detecting at least one of a plurality of electrical signals related to the pulse current from the electrical reference, A step of sequentially processing a selection of the most recent detected electrical signals to generate a baseline value for at least one electrical signal, wherein a detected electrical signal having a value on one side of the baseline is deemed to indicate no unpainted areas, and an electrical signal having a value on the other side of the baseline is deemed to indicate unpainted areas, The step of activating an unpainted signal when at least one of the detected electrical signals has the value of the other side of the baseline. A method that includes this.

2. The method according to claim 1, wherein the second contact is located at the top of the liner.

3. The method according to claim 1, wherein the second contact is located on the ground below the liner.

4. The liner has a top surface and a bottom surface, The bottom surface of the liner is conductive, The first and second contacts are in contact with the top surface of the liner. The method according to claim 1.

5. The method according to claim 4, wherein the liner is a geomembrane for geotechnical use on the ground.

6. The method according to claim 5, comprising a plurality of liners connected at seams of the geomembrane.

7. The method according to claim 1, wherein the at least one electrical signal is a selected one of current intensity and voltage.

8. The method according to claim 1, wherein the at least one electrical signal includes both current intensity and voltage, the detected current intensity is processed sequentially to generate a baseline of current intensity, and the detected voltage is processed sequentially to generate a baseline of voltage.

9. The method according to claim 8, wherein the unpainted signal is generated when either the current intensity or the voltage passes the generated baseline.

10. The method according to claim 1, wherein at least one of energy averaging, filtering, and Fourier spectroscopy is used to generate the baseline from a plurality of recent detected electrical signals.

11. The method according to claim 1, wherein the baseline is a selected average of the most recent plurality of detected electrical signals.

12. The method according to claim 1, wherein the activated unpainted area signal is at least one of an audible sound and an alarm light.

13. The method according to claim 1, wherein the activated unpainted signal is a position indicator corresponding to an area of ​​the liner that is in contact with the first contact when the detected electrical signal indicates the value on the other side of the baseline.

14. The method according to claim 13, wherein the activated unpainted signal is at least one of the grid coordinates on the liner, an audio signal, a visual signal, and a GPS coordinate signal.

15. A sensor for detecting uncoated areas in the liner, A pulsing generator with an electrical reference, The electrode is configured to move and maintain on a contact point with a liner spaced apart from the generator electrical reference while the generator pulses current to the electrode, To detect at least one electrical signal related to the pulse current over time from the generator electrical reference, Processing at least one electrical signal detected during a selected period over the most recent selected period, and The process involves generating a baseline of at least one electrical signal such that a detected electrical signal showing a value on one side of the baseline is considered to indicate no unpainted areas, and an electrical signal showing a value on the other side of the baseline is considered to indicate unpainted areas. A processor designed to perform the following: A paint-out signal is activated when any detected electrical signal has the value of the other side of the baseline. A sensor equipped with the following features.

16. The sensor according to claim 15, wherein the electrical reference is positionable in the liner.

17. The sensor according to claim 15, wherein the processor is configured to detect one of a selected one of current intensity and voltage.

18. The aforementioned processor, It detects both current intensity and voltage, The current intensity is processed continuously to generate a baseline of the current intensity, and The voltage is processed continuously to generate a voltage baseline. The sensor according to claim 15, configured as described above.

19. The sensor according to claim 18, wherein the unpainted signal is activated when either the detected current intensity or the detected voltage is on the other side of the baseline generated therefrom.

20. The sensor according to claim 15, wherein the processor is configured to generate the baseline from a plurality of recent detected electrical signals using at least one of energy averaging, filtering, and Fourier spectroscopy.

21. The sensor according to claim 15, wherein the activated unpainted area signal is at least one of an audible sound and an alarm light.

22. The sensor according to claim 15, wherein the unpainted signal is a position indicator corresponding to an area of ​​the liner that is in contact with the electrode at a time when the detected electrical signal value is on the other side of the baseline.

23. A method for detecting uncoated areas in a liner, A step of creating a circuit for current from the generator to the first contact and the liner to the second contact spaced apart from the first contact to the generator, wherein the second contact is the electrical reference of the generator, The steps include sending current from the generator to the first contact of the liner when the first contact moves along the liner, The steps include detecting the current intensity and voltage in the generator electrical reference, A step of comparing the baseline current intensity with the current intensity in the generator electrical reference, The steps include comparing the voltage in the generator electrical reference with the baseline voltage, A step of activating an unpainted signal, which is activated when either the current intensity or voltage has a value on one side of its baseline that is considered to indicate an unpainted area. Methods that include...

24. The liner has a top surface and a bottom surface, The bottom surface of the liner is conductive, The method according to claim 23.

25. The method according to claim 24, wherein the first and second contacts are in contact with the top surface of the liner.

26. The method according to claim 23, wherein the liner is a geomembrane for geotechnical use on the ground.

27. The method according to claim 25, comprising a plurality of liners connected at seams of the geomembrane.

28. The method according to claim 23, wherein the detected current intensity is continuously processed to generate a baseline of the current intensity, and the detected voltage is continuously processed to generate a baseline of the voltage.

29. The method according to claim 23, wherein the unpainted signal is generated when either the current intensity or the voltage passes through the generated baseline.

30. The method according to claim 23, wherein at least one of energy averaging, filtering, and Fourier spectroscopy is used to generate the baseline from a plurality of recent detected electrical signals.

31. The method according to claim 23, wherein the baseline is a selected average of the most recent plurality of detected electrical signals.

32. The method according to claim 23, wherein the unpainted signal that is activated is at least one of an audible sound and an alarm light.

33. The method according to claim 23, wherein the activated unpainted signal is an indication of a position corresponding to an area of ​​the liner in contact with the first contact when the current intensity indicates a value on one side of the current intensity baseline that is deemed to indicate an unpainted area, or when the voltage indicates a value on one side of the voltage baseline that is deemed to indicate an unpainted area.

34. A sensor for detecting uncoated areas in the liner, A generator having an electrical reference that is positionable in the liner or adjacent to the liner, The generator includes an electrode that moves and maintains on a contact point with a liner spaced apart from the generator electrical reference while supplying current to the electrode, The current intensity of the generator electrical reference, and Voltage of the generator electrical reference A detector that detects, The current intensity of the generator electrical reference is compared with the baseline current intensity, and The voltage of the generator electrical reference and the baseline voltage are compared. A processor designed in this way, An unpainted area signal is activated when the detected current intensity indicates a value on the side of the baseline current intensity that is considered to indicate an unpainted area, or when the detected voltage indicates a value on the side of the baseline voltage that is considered to indicate an unpainted area. A sensor equipped with the following features.

35. The aforementioned processor, The current intensity is processed continuously to generate the baseline current intensity, and The baseline voltage is generated by continuously processing the voltage. The sensor according to claim 34, configured as described above.

36. The sensor according to claim 35, wherein the processor is configured to generate the baseline from a plurality of recent detected electrical signals using at least one of energy averaging, filtering, and Fourier spectroscopy.

37. The sensor according to claim 35, wherein the unpainted signal is activated when either the detected current intensity or the detected voltage is on the side of the generated baseline which is considered to indicate an unpainted area.

38. The sensor according to claim 34, wherein the activated unpainted area signal is at least one of an audible sound and an alarm light.

39. The sensor according to claim 34, wherein when the detector detects that at least one of the current intensity and voltage indicates a value on its baseline side which is considered to indicate an unpainted area, the unpainted signal is a position indicator corresponding to an area of ​​the liner in contact with the electrode.

40. A sensor that defines a circuit for detecting unpainted areas in a liner having a changing contour, A generator with electrical standards, A contact that receives current from the generator and moves on an area of ​​the liner spaced apart from the generator electrical reference while the generator sends current to the contact, and the contact follows the changing contour of the liner area. A sensor equipped with the following features.

41. The sensor according to claim 40, wherein the contact is a flexible conductive sheet.

42. The sensor according to claim 40, wherein the contact is a flexible chainmail.

43. The aforementioned contact, A trolley rolling on top of the guide vehicle, A flexible conductive cable supported between the aforementioned guide wheels, Multiple conductive rollers spaced apart along the cable, each roller being rotatable around the cable The sensor according to claim 40, comprising:

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