Sumitomo Metal Industries, Inc.

Other

Tokyo Electron Limited

Tatsuo Hiroshima

Takahide Sakamoto

Toshiyuki Matsumoto

Yoshihiro Hirota

Tetsuya Hirota

Muneo Harada

Koichi Nakano

Toshio Shiraiwa

Toshihiko Sakai

Yoshiyasu Sakamoto

Kenichi Matsui

Ichiroh Ohgaki

Tetuo Asano

Noriyuki Matsubara

Kenichi Miyata

An electrostatic capacitance sensor, includes an electrostatic capacitance detector, an operational amplifier in which a feedback impedance circuit is connected between an output terminal and an inverse input terminal of the operational amplifier, a signal line connected between the inverse input terminal of the operational amplifier and the electrostatic capacitance detector, an alternating-current signal generator connected to a non-inverse input terminal of the operational amplifier, and a shield for shielding at least a portion of the signal line, the shield being connected to the non-inverse input terminal of the operational amplifier and the alternating-current signal generator. The electrostatic capacitance detector includes a detecting electrode and a shield electrode. The detecting electrode includes a detector-detecting electrode for detecting an object to be detected and an electrode introducer-detecting electrode for introducing an electrode to the detector-detecting electrode. The shield electrode is connected to the shield. At least a portion of the electrode introducer-detecting electrode is shielded by the shield electrode.

Electrostatic capacitance sensor, electrostatic capacitance sensor component, object mounting body and object mounting apparatus

A impedance-to-voltage converter for converting an impedance of a target to a voltage is described which comprises an operational amplifier (OP), a coaxial cable consisting a signal line and shielding element(s), and an AC signal generator. A feedback impedance circuit is connected between output and inverting terminals of the OP, and whereby a non-inverting terminal and the inverting terminal are an imaginal-short condition. One end of the signal line is connected to the inverting input terminal of the OP and the other end is connected to one electrode of the target and the AC signal generator is connected to the non-inverting input terminal of the OP. The shielding element comprises at least one shielding layer surrounding the signal line and is connected to the non-inverting input terminal of the OP, and thus the signal line and the shielding layer are the same voltage due to the imaginal-short of the input terminals of the OP, resulting in reduction of noise on the signal line.

Impedance-to-voltage converter

A static capacitance-to-voltage converter is capable of converting a static capacitance into a voltage without suffering from a stray capacitance formed between a signal and a shielding line or a stray capacitance formed between an exposed portion of the signal line and its surroundings. The static capacitance-to-voltage converter is formed of an operational amplifier placed in an imaginary short-circuit state between an inverting input and a non-inverting input thereof; a signal line having one end connected to the inverting input and the other end capable of being connected to a static capacitance; a shielding line surrounding the signal line and connected to the non-inverting input; an alternating current signal generator for applying the non-inverting input with an alternating current signal; and zero adjusters for adjusting the output of the static capacitance-to-voltage converter to minimum when no static capacitance is connected to the signal line.

Static capacitance-to-voltage converter and converting method

A method and apparatus for measuring a liner thickness of a zirconium liner provided at the inner surface of a zirconium alloy tube, the principle of measurement of which is to insert coils into the tube to generate an eddy current, detect the impedance component in the direction perpendicular to the direction of coil impedance change caused by the lift-off variation between the coils and the inner surface of tube, and obtain the liner thickness on the basis of the impedance component. In a case where the lift-off variation is larger, the impedance component in the direction of coil impedance change caused by the lift-off variation is detected, so that the component is used to correct the impedance component perpendicular to the same, thereby obtaining the liner thickness in accordance with the corrected values.

Zirconium liner thickness measuring method and an apparatus therefor for

A flaw detection apparatus for detecting flaws at the outer surface of a product, such as a steel bar, wire or steel pipe, which is round in section and produced by the hot rolling, by use of a probe of non-contact type and rotating around the product to be inspected, the apparatus providing a means for suppressing vibrations of an object to be inspected, a means for measuring a distance (lift-off) between the object to be inspected and the probe, and a means for carrying out positional control on the basis of the detection result of the lift-off measurement so that the axis of rotation of probe is allowed to be coincident with the axis of object to be inspected. In a case of using the eddy current inspection for the flaw detection, two coils of standard comparison system are used and a mixed signal of a plurality of frequencies is applied to the coils so that a signal obtained by the probe coils suppresses the signal component caused by the lift-off variation and corrects the flaw signal caused by existence of the signal component, thereby eliminating the influence of lift-off variation and enabling measurement with high accuracy.

Rotary probe apparatus for detecting flaws in a test object

A technique for detecting flaws in a metal product which uses a combined eddy current and magnetic flaw detection technique. A first magnetic field having flux lines parallel to the surface of the test object and a second field having flux lines perpendicular to the surface of the test object are generated. The resultant magnetic field is affected by faults in the metal test object. A magnetic field detector adjacent the test object detects the resultant magnetic field and produces an output signal which is processed by a circuit to provide a pair of component signals representing the portion of the output signal corresponding to the individual components of the resultant magnetic field, thus providing an indication of the type of faults that are present in the test object. One, or both, of the individual magnetic fields can be generated by an electromagnet which is driven by an alternating current to thereby produce a rotary resultant magnetic field, thereby allowing greater flexibility in detecting all types of flaws.

Method and apparatus including a flux leakage and eddy current sensor

Method and apparatus for conditioning of steel surface

Steel surface inspection apparatus

A cutting apparatus lights the surface of a moving hot steel material with lamps, locates any flaw with a video camera or the like, scarfs the surface of the steel material adjacent the flaw with a scarfing torch, measures the depth of the flaw with an eddy current detecting probe or the like, estimates accurately the loss of length due to conditioning size and depth of the flaw with a computer, and cuts the steel material in a predetermined length plus the accurately estimated length corresponding to the loss of length due to conditioning.

Hot steel cutting apparatus

The present invention is an automatic sensitivity adjustment apparatus for calibration of a nondestructive inspection instrument with a reference standard. Calibration is performed by setting the gain of a variable gain amplifier while a reference standard containing a standard flaw is passed before the sensing means of the instrument. A discriminator circuit connected to the sensing means detects when the output of the sensing means exceeds a predeterminedlevel. A hold time controller sends a sampling enable signal to a peak hold circuit which is also connected to the sensing means to cause the peak hold circuit to sample the sensing means output. The hold time controller senses the peak in the response of the sensing means and causes the peak hold circuit to hold that peak value. The output of the peak hold circuit is applied to the input of a variable gain amplifier. A comparator compares the output of the variable gain amplifier with a reference voltage produced by a reference voltage setting means. The output of the comparator is connected to the gain control input of the variable gain amplifier in order to control the gain of the variable gain amplifier so that the output level equals the reference voltage. Switching means disables the automatic sensitivity adjustment apparatus with the gain of the variable gain amplifier thus set during the ordinary operation of the non-destructive inspection apparatus.

Automatic sensitivity adjustment apparatus for calibration of a

A method is provided for balancing the sensitivity of two channels comprising intermittently-appearing pulse waves, such as the signals generated by respective sensors in a detecting couple which is used in the so-called differential detection of flaws in materials. The balancing of the levels of the pulse signals is accomplished by the use of, essentially, a pair of sample and hold circuits, one or two variable gain amplifiers and the same number of comparison loops as variable gain amplifiers.

Method for balancing the sensitivity of two channels in a differential

In a high-temperature furnace such as a heating furnace, a melting furnace or a blast furnace, a cooling cell assembly of a ferromagnetic material such as iron is used in the furnace wall. The thickness of the cooling cell assembly can be detected by winding primary and secondary windings about an iron core, passing an alternating current through the primary winding and inserting a sensor in an inspection hole for detecting the current or voltage induced in the secondary winding, forming a magnetic circuit in the sensor and a portion of the furnace wall, and detecting variations in magnetic permeability between the cooling cell assembly and mortar, refractory bricks or air gaps.

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Narita, Japan

Tatsuo Hiroshima