45results about "Resistance/reactance/impedence" patented technology

Sensor circuits for the measurement of small variations in the value of a sensing capacitor. An alternating voltage excites the sensing capacitor a predetermined frequency whereby the voltage on the sensing capacitor reverses polarity. This voltage on the sensing capacitor is sampled each time the voltage reverses polarity. An accumulator accumulates the sampled charges from the sensing capacitor. An output signal that represents the charge in the charge accumulating means indicates the measured capacitance.

A sample measurement device (110), in which a biosensor (30) having an electrode is mounted, voltage is applied to the electrode, and the concentration of a specific component in a sample deposited on the biosensor (30) is measured, comprises a voltage source (19) configured to apply voltage to the electrode, a time measurement component (22), and a controller (18) configured to control the voltage to be applied and measure the concentration of the specific component. The time measurement component (22) measures a detection time, which is the length of time between the mounting of the biosensor (30) and the deposition of a sample on the biosensor (30). The controller (18) changes a set value for measuring the concentration of a specific component according to the detection time. Consequently, measurement accuracy can be improved regardless of the temperature of the biosensor (30).

The invention provides an impedance measurement method of a three-phase alternating current system. The impedance measurement method of the three-phase alternating current system includes the following steps that a frequency sweeping signal sent by the output end of a network analyzing instrument is linked with a frequency detecting link, and the real-time frequency of the frequency sweeping signal is obtained through the frequency detecting link; the real-time frequency obtained by the frequency detecting link subtracts or adds a synchronizing frequency according to the measuring step. After the frequency is processed and obtained through the mentioned steps, an angle changing along with variation of the frequency is obtained through an integration element and consequentially, a sinusoidal signal is further generated and injected into a detected system. A voltage and current signal of a boundary of a system source module and a loading module is collected to carry out dq conversion. The converted signals are sequentially returned to the network analyzing instrument through a multiplexer. Two sets of voltage and current signals which are eight in total are obtained by the network analyzing instrument and used for setting up equation sets, the equation sets are combined for concluding a solution and then, the impedance of the detected system can be obtained. The set-up testing system is simple in structure and late-stage data are easy to process.

A circuit is provided wherein a test pulse is provided to a device under test. A module allows the test pulse to pass through to the device under test. The module blocks a reflected pulse from passing through to the device under test when the reflected pulse has an opposite polarity from the polarity of the test pulse. In some cases, the reflected pulse may be detrimental to the device under test if it is not prevented from reaching the device under test. In one embodiment, when a second reflected test pulse is traveling away from the device under test, the module allows the second reflected test pulse to pass through.

The present invention relates to a method for evaluating the crosslink degree of a vulcanized sample in real time during a vulcanization process or diagnosing the electrical properties of the sample after the completion of the vulcanization process, and then determining an optimal vulcanization time and an optimal content of each constituent gradient of a composition for vulcanization that optimize the properties of the composition according to the vulcanization conditions, for the sake of improving the properties of the vulcanized sample prepared from a polymer by vulcanization at a high temperature.The method for determining an optimal vulcanization time and an optimal content of each constituent gradient of a composition for vulcanization that optimize the properties of the composition according to the vulcanization conditions includes: (a) measuring an impedance spectrum in a specific frequency range in the individual vulcanization condition; (b) approximating the measured impedance spectrum to an equivalent circuit model consisting of resistance and capacitance components; (c) determining a polymer resistance Rp (i.e., a value obtained by subtracting a real part of the impedance measurement at a maximum frequency from a real part of the impedance measurement at a minimum frequency, or the magnitude of a real part of the semicircle in a Nyquist diagram) from the determined parameters; (d) determining, as an optimal end point of vulcanization, a time point at which the increasing rate of the polymer resistance Rp rapidly slows down; and (e) determining the optimal content of each constituent ingredient of the composition for vulcanization when the polymer resistance Rp of the sample completely vulcanized is at its minimum.