摘要:
A multi-point probe for testing electrical properties of a number of specific locations of a test sample comprises a supporting body defining a first surface, a first multitude of conductive probe arms (101-101'''), each of the probe arms defining a proximal end and a distal end. The probe arms are connected to the supporting body (105) at the proximal ends, and the distal ends are freely extending from the supporting body, giving individually flexible motion to the probe arms. The probe arms together with the supporting body define lines of contact between each of the probe arms and the supporting body and each of the lines of contact defines a perpendicular bisector being parallel to the first surface. The conductive probe arms originate from a process of producing the multi- point probe including producing the conductive probe arms on the supporting wafer body in facial contact with the supporting wafer body and removal of a part of the wafer body providing the supporting body and providing the conductive probe arms freely extending from the supporting body. Each of the probe arms defines a maximum width perpendicular to its perpendicular bisector and parallel with its line of contact with the supporting body, and a maximum thickness perpendicular to its perpendicular bisector and its line of contact with the supporting body. The maximum width and the maximum thickness define a ratio in the range of 0.5-20, such as 1-10, preferably 1-3, and each of the probe arms has a specific area or point of contact (111-111''') at its distal end for contacting a specific location among the number of specific locations of the test sample. At least one of the probe arms has an extension defining a pointing distal end providing its specific area or point of contact located offset relative to its perpendicular bisector.
摘要:
According to an aspect of an embodiment, a highly-sensitive resistance measuring device of solder bumps (20-11,20-12,20-13) comprises a resistance variation detection unit which detects a differential voltage (ΔV=V1-V2), which is obtained by subtracting a second voltage (V2) generated in a reference bump connection unit by a constant current (I) from a second constant current source from a first voltage (V1) generated in a monitored bump connection unit by the constant current (I) from a first constant current source, as a resistance variation voltage representing a resistance variation (ΔR) of the monitored bump connection unit.
摘要:
This invention relates to a method and apparatus for monitoring the earth loop impedance of an electrical installation that is protected by a circuit protection device, such as a residual current device. The method and apparatus enabling an earth loop impedance test to be performed on an electrical installation without tripping the circuit protection device. In use, the present invention is achieved using an earth loop impedance tester that automatically signals to any circuit protection devices present in the electrical installation that an earth loop impedance test is about to be performed. The circuit protection device can detect the earth loop impedance tester's signal sequence which comprises a first part of the sequence to disable operation of the circuit protection device for a predetermined interval and a second part of the sequence to monitor the earth loop impedance of the electrical installation. The second part of the sequence, which monitors the earth loop impedance of the electrical installation, is representative of the normal supply frequency of 50Hz or 60Hz. After this predetermined interval during which an earth loop impedance test has been performed, the circuit protection device reverts back to its normal mode of operation.
摘要:
Method for measuring parameters in ferromagnetic steel structures, e.g. railway rails and drillpipes, to detect mechanical stress, damage or deterioration. On the monitored area devices for magnetization or demagnetization e.g. an electromagnet, will be installed according to need . Two or more electrodes for feeding of current, whereby a pulse shaped electrical voltage is applied. On another pair of electrodes the potential drop is measured. This voltage drop is compared with another voltage drop measured at known measurement conditions or is compared with calibration data for the object. The deviation between these voltages is analysed to quantify the relative or absolute deviations and based on this, the condition of the steel structure is estimated. The device can measure the transient voltage curves with reference to one or more of the magnetization curves and it includes algorithms for analysing the voltage response curve for determination of mechanical stress and/or fatigue and/or cracks and/or metal loss in steel materials.
摘要:
An electrophysiological device comprises a lead-off detector in the form of an electrical impedance detector and further a path from a supply voltage to a second voltage. The path comprises segments having electrical impedances, at least one of which is to be ascertained, and a measuring vertex. The electrical impedance detector further comprises a discriminator connected to the measuring vertex and arranged to evaluate an electrical measuring signal observed at the measuring vertex.
摘要:
Um eine Annäherung eines leitfähigen Körpers an eine mit einem kathodischen Schutzstrom beaufschlagte Fluid-Transportpipeline (1) festzustellen, wird zu vorgegebenen Zeitpunkten an wenigstens zwei Messstellen (3) an der Fluid-Transportpipeline (1) jeweils eine für den an der Messstelle entlang der Fluid-Transportpipeline fließenden Schutzstrom repräsentativer Spannungsmesswert (U1, U2) erfasst. Für jeden vorgegebenen Zeitpunkt wird aus den Spannungsmesswerten (U1, U2) jeweils zweier beabstandeter Messstellen eine für die Differenz der an den Messstellen entlang der Pipeline fließenden Schutzströme repräsentativer Schutzstromdifferenzwert gebildet. Aus der zeitlichen Änderung der für die vorgegebenen Zeitpunkte gebildeten Schutzstromdifferenzwerte wird dann wenigstens ein Wert abgeleitet, der eine Annäherung eines leitfähigen Körpers an die Fluid-Transportpipeline (1) zwischen den beiden Messstellen (3) anzeigen kann. Mit dem erfindungsgemäßen Überwachungsverfahren können insbesondere plötzliche Beschädigungen der Fluld-Transportpipeline zuverlässig festgestellt werden. Da der kathodische Schutzstrom für das erfindungsgemäße Verfahren nicht moduliert werden muss, ist das erfindungsgemäße Verfahren ohne besonderen technischen Aufwand und kostengünstig realisierbar.
摘要:
The invention relates to a method for measuring the resistance of a load connected to the secondary side of a rotation transformer (ÜT), preferably the ignitor (ZP) of an airbag. The resistance measuring is, to a large extent, not influenced by magnetic coupling between the coils (PW, SW) of the transformer (ÜT). In accordance with this method, the condenser (Ck) is submitted to a partial discharge twice in succession. In the first partial discharge, the condenser is continuously discharged and in the second partial discharge it is discharged gradually. After each partial discharge, the residual charge tension at the condenser (Ck) is measured, and the difference between the two values is calculated, thus giving a value for the resistance of the load (ZP) connected on the secondary side.
摘要:
Es wird ein Verfahren zur Ermittlung der Wanddicke eines Metallrohres beschrieben, mit folgenden Merkmalen:
a) Bereitstellen eines Metallrohres bestimmter Länge. b) Anordnen von zwei Klemmkontakten an dem Metallrohr in genau definiertem Abstand. c) Verbinden der Enden des Metallrohres mit einer Stromquelle d) Messen des Spannungsabfalls an dem Metallrohr zwischen den Klemmkontakten.
摘要:
The resistances of a pressure-sensitive resistance mat are arranged in the form of a matrix and can be measured with a high degree of accuracy and low circuitry requirements by virtue of the fact that the output of an operational amplifier is connected to each line conductor (LZ1, LZ2, LZ3, LZ4) and each column conductor (LS1, LS2, LS3, LS4, LS5) that is joined to the resistances (R11, ..., R54) of the matrix. A voltage can be applied selectively by controlling the operational amplifiers (OZ1, OZ2, OZ3, OZ4; OS1, OS2, OS3, OS4, OS5) in a corresponding manner. Each operational amplifier belonging to the line conductors or column conductors (OZ1, OZ2, OZ3, OZ4) is fitted with a specular circuit which detects the output current of the operational amplifier connected to said resistance and which flows through the respectively selected resistance (R11, ...,R54). A processor (PR) determines individual resistance values on the basis of currents flowing through the individual resistances (R11, ..., R54) and the voltages released thereon.