Abstract: In one aspect, the invention includes an apparatus comprising a semiconductor substrate receiving device with at least one extension configured to hold a semiconductor substrate within a liquid bath. The device is configured to have at least a portion of the extension at least periodically placed within the liquid bath. The extension comprises a conductive material at least partially coated with an insulative protective material. The insulative protective material is configured to protect the portion of the conductive material which is in the bath from physically contacting the liquid of the bath. The apparatus also comprises an electrode within the bath, and an electrical connection between the electrode and the conductive material of the extension. Additionally, the apparatus comprises a monitor configured to monitor a current flow state of a circuit comprising the electrode, conductive material of the extension, and liquid bath to determine if the circuit is in a closed state or in an open state.

Abstract: A method and device for monitoring insulation and fault current in an electrical alternating current network. The differential current formed by vectorial addition is detected between at least two network conductors. Load-cut occurs when the differential current exceeds a specific threshold value. In order to increase safety and to protect human beings, the amount of alternating current contained in the differential current is detected as a first network variable, and the network alternating current between at least both network conductors and between at least one network conductor and an equipotential bonding conductor or a neutral conductor is detected as a second network variable.

Abstract: An apparatus for monitoring the status of the insulation on the wire in a winding in a device comprises a surrogate sample of insulating material having a thickness and properties selected to fail before the failure of the insulation on the wires in the winding, and a detector for detecting and indicating failure of the sample of insulating material. A method of monitoring the status of the insulation on the winding in a dynamoelectric device includes associating a surrogate sample of insulating material with the winding, monitoring the surrogate sample, and providing an alarm when the surrogate sample fails, which is predictive of the failure of the insulation on the winding wire.

Abstract: This invention relates to an insulator for a multi-power system, which is used to resolve the current leakage which comes from each power supplied to the corresponding devices which are not being correctly operated. The isolating device includes: a first power supply for providing an operating power to the isolating device; a level detector for detecting the voltage level of the operating power; a signal isolation controller for changing the output level of the circuit supplied by the operating power based on the operating power detected; and a second power for supplying a real-time power to circuit for power saving operation based on the changed output level.

Abstract: TDDB test pattern which can reduce a test time period and improve a precision of a measurement result statistically; and a method for testing TDDBs of MOS capacitor dielectric films using the same, the TDDB test pattern including a plurality of unit test pattern cells each having an MOS capacitor, an MOS transistor, and a fuse for controlling operations of the MOS capacitor and the MOS transistor, a first voltage supplying unit for supplying a stress voltage to the MOS capacitor and the MOS transistor in each unit test pattern cell on the same time, an ammeter for continuous measurement of a total current from the plurality of unit test pattern cells, to measure a total time to breakdown of the plurality of unit test pattern cells, a plurality of VFN's (Voltage Forcing Nodes) each positioned between the first voltage supplying unit and the fuse in the unit test pattern cell, a DCMN (Drain Current Measuring Node) positioned between the ammeter and a drain terminal of the MOS transistor in each of the plur

Abstract: The diagnosis method of deterioration of electric power cable is that which diagnoses the deterioration accurately without a especial effort to reduce the harmonics in an electric power source equipment for test. Loss current component, which is obtained by rejecting the capacitive component of frequency f1 contained in the total current flowing in the insulation of the electric power cable, when superimposing a first voltage V1 of frequency f1 and a second voltage V2 of frequency f2 (V1≧V2) to an electric power cable, is measured. Further the current components and the frequency components contained in the current is investigated. The deterioration diagnosis is implemented by frequency components excepting the frequency f1, f2 and the their harmonic.

Abstract: The 4 mA-20 mA type or 0-20 mA type current loop connects an analog sensor (1) to an acquisition system (3), respectively carrying a sensor current (Ic) and an acquisition current (Ia). A test circuit is connected in parallel with the current loop to inject a superposition current (Is) into said loop, which current is superposed on the sensor current (Ic) or on the acquisition current (Ia). In a first embodiment, a variable voltage generator (7) injects the superposition current (Is) by adding it to the acquisition current (Ia), thereby making it possible to check a low-current threshold of the acquisition system (3). In a second embodiment, a variable current regulator injects the superposition current (Is) by adding it to the sensor current (Ic), thereby making it possible to check a high-current threshold of the acquisition system. The high- and low-current thresholds of the acquisition system are tested without opening the current loop.

Abstract: After a flexible printed circuit is left under an atmosphere of a water vapor pressure of not lower than 30 mmHg so as to absorb moisture, a voltage is applied between two wiring portions to thereby measure an insulation resistance value between the wiring portions during the voltage application. The quantity &Dgr;log(R) of the change of the insulation resistance value at regular intervals is obtained. An examination is made as to whether the maximum of the quantity &Dgr;log(R) of the change of the insulation resistance value is not larger than a predetermined reference value or not. From this examination, a judgment is made as to whether the flexible printed circuit is good or not.

Abstract: A fiber optic cable (10) is buried below ground, either by direct burial, or by being pulled through a previously buried duct. During cable burial, the instantaneous resistance between the sheath and ground (the sheath-to-ground resistance) is continuously monitored. If the instantaneous sheath-to-ground resistance drops below a prescribed value, an alarm is generated, signaling a sheath fault. During burial, the length of cable paid out and placed underground is monitored, thus providing an indication of the relative location of the sheath fault.

Abstract: Motor insulation degradation is determined using circuitry to sense the common mode leakage current from the ground wire cable. In a preferred embodiment of the invention, a small current transformer detects the common mode leakage current flowing in the ground wire cable of the motor controller circuit. A single pole low pass filter generates an average leakage current signal from the sensed current. The average leakage current signal is converted to a PWM signal. A pulse generator receives the PWM signal and generates pulse signals at the rising and falling edges of the PWM signal. A pair of level shifters receive the rising edge and falling edge pulse signals and transpose those signals from a floating high voltage to a voltage referenced to ground. A pulse reconstruction circuit receives the level shifted pulse signals and reconstructs a pulse width modulated signal having a duty cycle which varies with respect to the magnitude of the common mode leakage current.

Abstract: A stressing voltage is applied to a dielectric film (step S23). An A-SILC is monitored with stressing time and is plotted on a log-log scale (step S24). A straight line is applied to the plotting, a stressing time at which the line crosses a predetermined value of the A-SILC (a breakdown threshold) is obtained, and the obtained stressing time is predicted as the lifetime of the dielectric film (step S26).

Abstract: A broadband test procedure detects the onset of stator winding insulation damage, identifies the failure mechanism, determines the winding's susceptibility to further damage, and predicts stator winding failure. This is accomplished by realizing that changes in the stator winding insulation and/or geometry are reflected as changes in the capacitance between the individual windings and, hence, as changes in the stator winding's broadband impedance response. In the currently preferred approach, the impedance response includes the frequency, magnitude, width, and phase of the resonant impedance.

Abstract: An electromagnetic waveform developing in synchronism with a system power supply by a partial discharge of electric equipment such as a power distribution device is received by an antenna 1. From the electromagnetic waveform of measurement frequency included in the received signal, there are extracted a component changing according to the frequency of the system power supply and a component changing at the frequency twice that of the system power supply. The presence or absence of discharge is determined from the magnitude of each of the extracted components, thereby detecting a partial discharge.

Abstract: A device for sensing discharges in a test object (1) with two electric connection conductors (1a, 1b, 1c, 1d), preferably a cable joint, comprises at least one first and one second sensor (2a, 2b) and evaluation equipment (EVU). Each one of the sensors generates and supplies to the evaluation equipment sensor signals in dependence on current pulses through the connection conductors and the direction thereof, the first sensor a first sensor signal (v1) and the second sensor a second sensor signal (v2). The evaluation equipment generates in dependence on received sensor signals an indication signal (IND), indicating a partial discharge in the test object.

Abstract: For the electrical testing of base material for manufacturing printed circuit boards, firstly smooth edges to the copper layers of the base material, free of deformation, are produced, preferably in a milling process, which base material is subsequently subjected to testing for a sufficiently high level of electrical resistance between the two copper layers. Successful resistance testing is followed by testing for the dielectric strength of the insulating layer of the base material by measuring the current conduction produced as a result of a disruptive breakdown. This process serves to reduce the amount of processed base material which is rejected, on which, at the present state of the art, there is no electrical testing prior to processing.

Abstract: The insulation resistance of a capacitor is accurately measured within a short period of time by applying AC signals at two different frequencies f1 and f2 to the capacitor to measure the impedance Z1 and Z2 of the capacitor at each frequency. The series resistance Rs and capacity c of the capacitor are obtained from the impedance Z1 at the higher frequency f1, and the insulation resistance Rp of the capacitor is obtained from the impedance Z2, series resistance Rs and capacity C at the lower frequency f2.

Abstract: A method for measuring insulation resistance capable of removing the influences of piezoelectric noise which is occurring due to mechanical vibrations applied to an electronic component to measure the insulation resistance of the electronic component with high accuracy. In order to do so, a predetermined measured voltage is applied to the electronic component arranged in a position subjected to periodic mechanical vibrations from the outside to measure a current flowing through the electronic component. Then, the value of the measured current flowing through the electronic component is integrated over the period of the mechanical vibrations or over a time which is an integral multiple thereof. With this arrangement, a piezoelectric noise current can be cancelled and only a leakage current to be primarily measured can be extracted. Thus, by calculating the value of the insulation resistance from the value of the current, the insulation resistance can be detected with high accuracy.

Abstract: The method obtains a first C-V curve prior to irradiation with light and a second C-V curve after the irradiation with light. The method determines the amount of the intra-film impurity ions in an insulating film in the state prior to the irradiation with light, based on the first and the second C-V curves.

Abstract: A method for testing the reliability of a dielectric thin film. An exponential current ramp test is performed with a delay time to test the dielectric thin film. An exponential current ramp charge-to-breakdown distribution, which is represented by cumulative distribution failure percentage, is obtained. An exponential current ramp charge-to-breakdown at a cumulative distribution failure percentage is calculated. An exponential current ramp constant and a constant current stress constant at the cumulative distribution failure percentage are calculated. A constant current stress charge-to-breakdown at the cumulative distribution failure percentage is calculated by using a specified current density and the constant current stress constant at the cumulative distribution failure percentage. The constant current stress charge-to-breakdown at the cumulative distribution failure percentage is compared to a specified constant current stress charge-to-breakdown to determine the reliability of the dielectric thin film.

Abstract: To perform a reliable and calibrated measurement of partial discharges, a first calibratable sensor and a second sensor are arranged in a metal enclosure. The first calibrated sensor picks up signal components in the HF (High Frequency) range, and the second non-calibrated sensor picks up signal components in the UHF (Ultra-High Frequency) range. An HF signal component picked up by the first sensor is transmitted to a partial discharge analyzer. The opening time of the gate device is determined by a UHF signal component picked up by the second sensor.

Abstract: A method of screening varistors. In a first step, a pulse generator is caused to apply to a varistor a large-current pulse having a peak value of at least 1 A and 90% or less of an average breakdown current of the varistor and has a pulse width of 100 msec or less. In a second step, the dielectric loss of the varistor is measured through use of an LCR meter at a frequency of about 100 KHz or higher. Subsequently, in a third step, a judgment is made as to whether the measured value falls within a range that is preset as a reference value for judgment. If the measured value is within the range, the varistor is judged to be a non-defective product. If the measured value is outside of the range, the varistor is judged to be a defective product having an internal defect.

Abstract: A capacitance mapping tool consisting of an improved capacitance probe head assembly having an inflatable electrode bladder mounted at the end of a telescoping support pole is provided for enabling a service technician to accurately position the probe head assembly between stator bars of a large electric motor or power generator from a remote location. Using the tool, capacitance measurements of insulation on stator bars can be obtained without removing the field. The tool is constructed such that it can be inserted between the field generating component (e.g., the rotor) and the stator windings of a large motor or power generator, thus, precluding the need for field removal. A bendable articulated tip section, which remains in a particular bend arrangement until manually reconfigured, is provided at one end of the tool where the capacitance measuring probe head is attached.

Abstract: A method and an apparatus for monitoring conditions of electric insulation in a live or energized electric system. The invention takes into account the fact that, when the insulation resistance of an electric system is measured under real live conditions, the electric insulation works under voltages and current-leakage conditions which different from those measured in so-called “cold” state. The invention is based on two voltage measurements in one of which the operating conditions of the electric insulation are artificially changed for a known value. Insulation parameters are then calculated by a set of formulas using the results of the two measurements.

Abstract: A double-speed tester for a microelectronic device, in which a plurality of recesses is formed on the circumference of a test plate at an interval of step, the recesses each accommodating a microelectronic device which is measured with the test plate rotating.

Abstract: The insulation resistance of a capacitor is accurately measured within a short period of time by applying AC signals at two different frequencies f1 and f2 to the capacitor to measure the impedance Z1 and Z2 of the capacitor at each frequency. The series resistance Rs and capacity C of the capacitor are obtained from the impedance Z1 at the higher frequency f1, and the insulation resistance Rp of the capacitor is obtained from the impedance Z2, series resistance Rs and capacity C at the lower frequency f2.

Abstract: An apparatus and method for testing a coating on a conductor, such as a dielectric coating on a wire. A high voltage source is coupled to the conductor and the coating through a primary winding of a transformer. Faults in the coating will result in a change in current in the primary winding thus inducing current in a secondary winding of the transformer. Current in the secondary winding is detected by a sensor and fault data can be compiled by known data acquisition devices.

Abstract: A group of bushings receives voltage in parallel to produce a current output from each bushing. Cumulatively combining the current outputs from the bushings vectorially furnishes a vector sum bushing current. Reference voltage devices also produce reference current outputs. Cumulatively combining the reference current outputs vectorially provides a vector sum reference current, and differentially vectorially combining the vector sum reference current with the vector sum bushing current delayed by 90° provides a difference signal representative of a bushing condition. As an alternative to the reference voltage devices, a second group of bushings may be used. In this case, a delay of 90° is not required. The invention may also be used to monitor the condition of other capacitive devices, for example, high voltage current transformers.

Abstract: An apparatus and method for detecting a breach in an electrically insulating surface of an electrically conductive power system enclosure within which a number of series connected energy storing devices are disposed. The energy storing devices disposed in the enclosure are connected to a series power connection. A detector is coupled to the series connection and detects a change of state in a test signal derived from the series connected energy storing devices. The detector detects a breach in the insulating layer of the enclosure by detecting a state change in the test signal from a nominal state to a non-nominal state. A voltage detector detects a state change of the test signals from a nominal state, represented by a voltage of a selected end energy storing device, to a non-nominal state, represented by a voltage that substantially exceeds the voltage of the selected opposing end energy storing device.

Abstract: An apparatus for monitoring the status of the insulation on the wire in a winding in a device comprises a surrogate sample of insulating material having a thickness and properties selected to fail before the failure of the insulation on the wires in the winding, and a detector for detecting and indicating failure of the sample of insulating material. A method of monitoring the status of the insulation on the winding in a dynamoelectric device includes associating a surrogate sample of insulating material with the winding, monitoring the surrogate sample, and providing an alarm when the surrogate sample fails, which is predictive of the failure of the insulation on the winding wire.

Abstract: A method of initiating and monitoring partial discharges in an insulating medium is disclosed. Apparatus for performing the method is also disclosed. A relatively low frequency time varying exciting waveform is applied to a sample of an insulating medium. A trigger pulse of short duration is superimposed on the exciting waveform to initiate partial discharge activity in the sample. The apparatus includes a trigger pulse generator with a synchronizing circuit which provides a pre trigger signal for an oscilloscope, allowing the resultant partial discharge activity to be monitored.

Abstract: A safety compliance test instrument includes circuitry for performing insulation resistance and ground circuit tests such as a ground bond test, as well as high voltage AC and DC dielectric withstand or hipot tests. A micro-processor based controller provides control signals to a common power circuit, and accepts input of test parameters for all four tests through an integrated user interface including a keypad and menu display.

Abstract: Two-wire signal transmitter and method in which a very low-level Alternating Circuit (AC) input signal sensed at a remote circuit at a first end of a signal path is added to a low-level Direct Current (DC) bias signal provided by a local circuit that is located at a second end of the signal path. In a preferred embodiment, the remote circuit is electrically coupled to and powered by the local circuit through a two-wire path interconnection, typically a shielded twisted-pair cable. The DC bias signal has sufficient level to overcome minimum ratings of electrical contacts, thereby to pass the sensed very low-level AC input signal reliably through the poor electrical contacts that are used, for instance, for connecting electronic circuits that run the length of a railway train.

Abstract: A test instrument for testing magnet wire which is provided which tests, collects and permits analyzing the effect of temperature, frequency, voltage and rise time associated with magnet wire use, and more particularly, the effects of those variables on the insulation of the wire, so as to evaluate the magnet wire performance and inverter controlled dynamoelectric machine applications.

Abstract: The invention teaches a method for using a test liquid to simulate the effects of a coolant condensate on an electrical power station component in the event of an accident with an uncontrolled escape of coolant condensate, in which a film is formed on a surface of the power station component and then a resistance test of the power station component is performed. A test liquid formed of polyglycol ether which has a content of between 0.01 and 0.5 weight % dissolved in deionized water, a conductivity between 1 and 6 .mu.S/cm at room temperature, and a surface tension up to 50 mN/m at room temperature is provided. A power station component is coated with a film of the test liquid. A resistance check of the coated power station component is then performed.

Abstract: It is intended to provide a test method and a test apparatus for determining breakdown strength which are not affected by statistic capacity in measurement environment or the like, and can be applied to any semiconductor elements. A capacitor with known capacitance is connected to a semiconductor element, and voltage is applied to the capacitor to charge and discharge it. It is detected whether or not the semiconductor element is broken down at the moment of discharge. Either one of charge or energy injected in charging and discharging is calculated from the capacitance and voltage at the moment of breakdown, and the result of calculation is determined as the breakdown strength.

Abstract: A system for determining if there is a break in the shield or a compromise in the shielding effectiveness of coaxial cable plant by inducing a reference test signal onto the sheath or outer conductor of a coaxial cable. Concurrent testing is done with a digital sampling receiver for the presence of some of the induced reference signal on the inner or center conductor of the cable. The test current may be introduced directly onto the coax's sheath by magnetically coupling with a split ferrite core, or it may be applied indirectly by inducing the current onto a conductor, such as a grounding wire, that attaches to the coaxial cable. The test signal on the center conductor may be received back at the headend, or it may be received near the injection point by breaking the coaxial cable, or by connecting a probe to the center conductor. The invention may employ ranging to determine the distance to the shield break.

Abstract: A clamping mechanism for mounting a circuit condition monitoring device to electrical cables of various diameters includes a core member comprising a plurality of laminations arranged in a generally rectangular configuration. A spring spanning the core member is anchored at one end to the core at a point near the housing of the monitoring device and at the other end is attached to a bridging member affixed at the opposite end of the core near the housing. This allows the spring to expand less as it transverses the bridge in order to accommodate different power cable diameters.

Abstract: An insulated device diagnosing system is capable of judging the deterioration, lifetime, and defects of a device. The intensity at each voltage phase angle is measured at a plurality of specific frequencies, taking high voltage phase angles as the abscissas. The deterioration, lifetime, and the kind and extent of abnormality of the device are judged from the pattern and intensity of the spectral distribution, which is obtained by peak-holding the measured intensity for a defined time period. According to the present invention, partial discharge can be measured highly sensitively and precisely to diagnose the deterioration, lifetime and the extent of defect of the device. As a result, the insulation reliability of the device can be improved, and the part of the device that should be repaired/replaced can be grasped before disassembly of the device, thereby cutting the maintenance cost.

Abstract: An apparatus for detecting an insulation defect in at least one device connected into an electrical power transmission or distribution network and having: leakage current measuring sensors (10) arranged on a ground line (19a, 19b, 19c) of the device; a measurement signal analogue/digital converter (58, 60); and a signal processing unit (14) including a comparison circuit (75) for comparing the measurement signal with a maximum threshold value representative of the maximum value of the leakage current permitted to flow in the ground line (19a, 19b, 19c), to obtain an insulation defect signal. The processing unit (14) includes a discriminator circuit (76) for discriminating, in the insulation defect signal, between a component of a useful signal and a component of a disturbance signal.

Abstract: The present invention discloses a novel method and apparatus for de-etching pin-holes in a passivation layer that is deposited over a metal conductor layer on the surface of a semiconductor wafer by utilizing a substantially clear, electrically conductive film as a top electrode immersed in an electrolyte for observing under an optical microscope bubbles generated from a pin-hole on the wafer surface which functions as a bottom electrode when a DC current is flowing through the top electrode, the electrolyte and the bottom electrode such that gases in the form of bubbles are generated at the pin-hole site where metal is exposed to the electrolyte.

Abstract: A voltage value of an impulse voltage repetitively applied on a test-piece coil is increased in accordance with time elapse. A terminal voltage applied on both ends of the test-piece coil is monitored to detect an electric breakdown of the test-piece coil. Upon detecting such a breakdown, application of the impulse voltage is immediately stopped to prevent the test-piece coil from being unnecessarily damaged. Meanwhile, a voltage value of the impulse voltage is measured quantitatively at the time the electric breakdown is detected and the measured data is stored in a memory, so that the memorized data can be used later as a breakdown voltage value.

Abstract: A charged voltage between the ground and a positive pole of backup capacitor 5 and a ground-casing voltage developed between the ground and a casing of capacitor 5 are determined. When the ground-casing voltage is smaller than a first value, it is judged that capacitor 5 has an opened circuit on its positive pole side; when the ground-casing voltage is larger than a second value, it is judged that capacitor 5 has an opened circuit on its negative pole side. A difference between the ground-casing voltage and the charged voltage is divided by the ground casing voltage so that a coefficient is obtained. When the coefficient is outside a predetermined range of values, it is judged that capacitor 5 is poor in capacitance, which makes it possible to determine, even in operation, whether capacitor 5 functions properly.

Abstract: A method and apparatus for detecting partial discharges in cables and accessories. An electrical interruption is created in, for example, the sheath conductor of a cable, and the voltage of high frequency signal components, created by a partial discharge, is measured across the interruption. The interruption is short-circuited to allow low frequency signals to pass across the interruption, thus preventing low frequency signals from being measured. This is useful because the signal/noise ratio of the frequency range measured according to this invention is more favourable. Also, in order to properly and accurately measure a partial discharge, it is important to relate measurements to the main supply voltage of the cable. The present invention also provides a method wherein prior to display the signal is combined with a signal representing the main supply voltage.

Abstract: A system for detecting faults in the insulation layer surrounding a concealed conducting pipe (10) includes a signal generator (12) for applying an alternating current with a frequency of around 4Hz to the pipe, a magnetometer (102) for detecting the alternating current from the pipe (10) and a CPU (115) for identifying changes in the gradient of the detected current along the length of the concealed conducting pipe (10) which are caused by the faults in the insulation layer. The magnetometer (102) is used in connection with a locator(100) which detects a second alternating current applied to the pipe (10) by the signal generator (12), this second alternating current having a frequency of around 128Hz. The system can also use both these signals to determine the direction of the signals emulating from the pipe (10).

Abstract: A materials characterization test cell is disclosed. The test cell includes a housing including spacers for supporting sample insulation materials, and a channel disposed in the housing to permit the passage of oil through the housing. A pair of electrodes is provided to provide a mechanism for making polarization spectrum and/or streaming electrification measurements.

Abstract: The reliability of thin film insulators is determined with noise measurements which find the barrier height mean and standard deviation. A constant voltage source is applied across the thin film insulator. A low noise amplifier is connected across a resistor which is in series with the insulator. A spectrum analyzer is connected to the low noise amplifier. The power density is obtained by observing the output of a spectrum analyzer. The current spectral density is compared to a predetermined reference to detect the presence of defects in the insulator.

Abstract: In an accident involving the uncontrolled escape of coolant, a condensate film forms on the power station components. Due to deposited dirt it is conductive, and if the insulation has aged it can cause electrical function defects. That situation is simulated by spraying a test liquid, having a wetting power (surface tension) and a conductivity which correspond to the coolant condensate, onto the electrical power station components. The testing can be carried out on a routine basis at normal pressure and normal temperature during ongoing reactor operation.

Abstract: A remote contamination sensing device for contamination on insulation of electric power lines and substations includes a data logger and a supporting structure to which a sensing capacitor with at least two conductors is attached such that the conductors are spaced apart and insulated from each other. A capacitance measuring device, for measuring capacitance data between the conductors, is connected to the data logger. A hygrometer, for measuring the relative humidity of the ambient air, is also connected to the data logger. A first temperature sensor, for measuring the ambient temperature, and a second temperature sensor, for measuring the surface temperature of the capacitance sensor, are connected to the data logger. The measured capacitance data, relative humidity data, ambient temperature data, and surface temperature data are stored in the data logger.

Abstract: A remaining life of a stator coil resulting from galvanic corrosion between different kinds of metals in a rotating machine adopting a water cooling system and remaining life of a stator coil's insulating layer resulting from a wet heat degeneration can be positively and integrally evaluated according to the present invention by sampling a brazing section between the stator coil clip and copper wires, cutting off the sampled brazing section in a copper wire array direction, measuring a joined section brazed with a brazing material as a copper wire direction length and finding an effective sealing length of that brazing section or sampling an insulating layer of the stator coil, finding infrared spectra of the insulating layer, comparing the infrared spectra of the insulating layer of the stator coil with infrared spectra of a healthy stator coil's insulating layer not penetrated by water, finding difference spectra of an ester group of an epoxy resin used as a bonding agent of the insulating layer and predict

Abstract: A clamping mechanism for mounting a monitoring device to an electrical cable includes a core assembly formed by a plurality of laminations secured together and arranged in a generally rectangular configuration. A spring spanning the core is anchored at one end to the core at a point near the housing of the monitoring device and at the other end is attached to a bridging member affixed at the opposite end of the core near the housing. This allows the spring to expand less as it transverses the bridge in order to accommodate different power cable diameters.