Abstract: The present disclosure provides an impedance measurement circuit for measuring and detecting variations in an impedance under test, and methods of operating the impedance measurement circuit. The impedance measurement circuit comprises a plurality of converts, including at least two digital-to-analog converters (DACs). The DACs together alternate between a first mode of operation and a second mode of operation. In the first mode, a first one of the DACs is operational to convert a first digital input signal to a first analog output using a first hardware component, and a second one of the DACs is operational to convert a second digital input signal to a second analog output using a second hardware component.

Abstract: A method includes measuring first travelling wave power of a microwave having a single frequency peak and second travelling wave power having a single frequency peak, acquiring duty ratios of the first travelling wave power and the second travelling wave power based on measured values and a first determination threshold value, measuring third travelling wave power of a microwave having a bandwidth and fourth travelling wave power having a bandwidth, acquiring duty ratios of the third travelling wave power and the fourth travelling wave power based on measured values and a second determination threshold value, approximating a pulse width error between the first travelling wave power and the third travelling wave power and a pulse width error between the second travelling wave power and the fourth travelling wave power with linear functions, and determining the correction function based on the linear functions.

Abstract: A sensor for detecting a medium, including a capacitive measuring device having at least two electrodes and at least one dielectric, and including an electronic device, which is configured to ascertain a variable regarding and/or dependent on capacitance and to determine an information item regarding the presence of the medium and/or its concentration in view of the ascertained variable; the electronic device being additionally configured to vary a voltage applied between the electrodes, using at least two frequencies, the variable being ascertainable for each of the frequencies, with the aid of the electronic device, a deviation variable regarding a deviation of the variables ascertained for the different frequencies from one another being able to be determined, and the information item being able to be determined in additional view of the deviation variable. In addition, the present invention relates to a method for operating a capacitive measuring device.

Abstract: A non-destructive, inline, multi-channel fabric conductivity measurement system uses an array of opposing paired transmit/receive microwave horns on opposite sides of a fabric material moving in a production line, each horn pair corresponding to a channel in the system. A processor-based controller can control channel hopping, frequency hopping, and measurement orientation to acquire measurements of material conductivity and anisotropy, which measurements can be analyzed for defects that can be flagged in real time during production. Measurements and/or analyses can be stored to make roll-to-roll, batch-to-batch, day-to-day, or production-phase-to-production-phase comparisons useful in identifying the sources of production problems and/or the causes of corrections.

Abstract: An in situ ultra-low power contactless measurement apparatus and method suitable for micro-electronics in big data applications for continuously reporting a soil moisture profile at various zones.

Abstract: A capacitive sensor may include a transmit electrode and a receive electrode capacitively coupled with the transmit electrode. A capacitance sensing circuit senses a capacitance between the transmit and receive electrodes by applying a signal to the transmit electrode and rectifying a current waveform induced at the receive electrode. A compensation circuit reduces the effect of a mutual and parasitic capacitances of the transmit and receive electrode pair by adding a compensation current to the rectified current.

Abstract: A circuit includes a stacked circuit layer, a plurality of test contact points, and a comparator. The stacked circuit layer includes a plurality of reference capacitors each having a reference capacitance. Each of the test contact points is electrically connecting to an under-test capacitor of an under-test module. The comparator compares the reference capacitance of one of the reference capacitors with an under-test capacitance of the under-test capacitor corresponding to one of the test contact points to measure a range of the under-test capacitance.

Abstract: In accordance with an embodiment, a method of controlling a power supply node includes measuring a voltage of the power supply node, determining a first current based on the measuring, determining a first current and a second current based on the measuring, and summing the first current and the second current at the power supply node. Determining the first current includes operating a first controller having a first bandwidth, and determining the second current includes operating a second controller having a second bandwidth greater than the first bandwidth.

Abstract: Apparatus and associated methods relate to a load-cell measurement system having an output that is substantially independent of the system voltage source, by providing compensation for the source voltage variation using both a compensating offset voltage and a compensating reference voltage, these compensating voltages having a predetermined relationship with each other. In an illustrative example, the supply voltage may be directly connected to a load-cell, an instrumentation amplifier, and a compensation circuit. In some examples, the compensation circuit may include a chain of impedances which may generate two mutually related voltages both being scaled to the supply voltage. The first scaled voltage may, for example, substantially compensate offset of the load-cell measurement system. The second scaled voltage may, for example, substantially compensate for gain.

Abstract: A technique detects an abnormal signal in a compound sampled signal recorded in the time domain. The technique involves dividing the sampled signal recorded in the time domain into sample segments; transforming each of the sample segments from the time domain into the frequency domain to determine transformed segments, each transformed segment having frequency points, each frequency point having an amplitude associated with a certain frequency; for a frequency point in a given transformed segment, determining a ratio by dividing the amplitude of the frequency point by a value indicative of an average of the amplitudes of the frequency points at the same frequency across transformed segments; repeating the determination of a ratio for frequency points in each transformed segment to determine ratios for each transformed segment; repeating the determination of ratios for transformed segments; and using the ratios to detect the abnormal signal in the compound sampled signal.

Abstract: A voltage sensing device with which high-precision voltage sensing is possible without the need to obtain a unique correction constant for each device. A pair of voltage input nodes NCk and NCk-1 is selected from voltage input nodes NC0-NCn in switch part 10, and they are connected to sensing input nodes NA and NB in two types of patterns with different polarity (forward connection, reverse connection). Sensing input nodes NA and NB are held at reference potential Vm by voltage sensing part 20, and current Ina and Inb corresponding to the voltage at voltage input nodes NCk and NCk-1 flows to input resistors RIk and RIk-1. Currents Ina and Inb are synthesized at different ratios in voltage sensing part 20, and sensed voltage signal S20 is generated according to the synthesized current Ic. Sensed voltage data S40 with low error is generated according to the difference between the two sensed voltage signals S20 generated in the two connection patterns.

Abstract: A method and device are provided for demodulation of an output signal from a transducer (1) driven by an alternating excitation signal having an excitation frequency. The transducer produces an amplitude-modulated output signal (y(t)) containing the quantity to be measured. The device has sampling units (5,6,7) to sample the output signal from the transducer and the output signal from the excitation unit, and a computation unit (8) to compute a first complex valued quantity ( Y) including information on the amplitude and phase of the output signal at the excitation frequency based on sampled values of the output signal from the transducer, compute a second complex valued quantity (?, ?) including information on the amplitude and phase of the excitation signal at the excitation frequency based on sampled values of the excitation signal, forming a complex valued output quotient between the first and second complex valued quantities, and compute the demodulated output signal (Od) based on the output quotient.

Abstract: A method and system for calibrating a plurality of measurement systems. The method includes obtaining a first plurality of calibration standards. The first plurality of calibration standards is associated with a plurality of predetermined values. Additionally, the method includes measuring the first plurality of calibration standards by a plurality of measurement systems to obtain a first plurality of measured values, processing information associated with the first plurality of measured values, and selecting a first measurement system from the plurality of measurement systems based on at least information associated with the first plurality of measured values. Moreover, the method includes calibrating the first measurement system with the first plurality of calibration standards, obtaining a second plurality of calibration standards, and measuring the second plurality of calibration standards by the first measurement system to obtain a second plurality of measured values.

Abstract: MOSFETs are provided to connect the sensor input terminals of a ratiometric output sensor to a pair of power terminals, and the gate of each MOSFET is coupled to the opposite power terminal so that both MOSFETs are rendered conducting to power the sensor when a supply voltage of a predetermined polarity is connected across the power terminals but one of the MOSFETs is rendered non-conducting when a voltage of the opposite polarity is so applied. The MOSFET that is rendered non-conducting is oriented so that any internal source-drain diode does not bypass current around the MOSFET when voltage of the opposite polarity is applied. Optionally, over-voltage protection is provided by an input voltage sensor controlling the other MOSFET through a third MOSFET.

Abstract: The invention relates to a device for analyzing the composition of the contents of a container, comprising: electromagnetic field emitting/receiving means (40) at least several frequencies comprised in a determined range of frequencies, means (22) supporting a container (R), the contents of which have to be analyzed, suitable for ensuring accurate relative positioning between the emitting/receiving means (40) and the container (R), means (50) capable of measuring the complex impedance of the emitting/receiving means influenced by the load formed by the container (R) and its contents, representative of the complex dielectric characteristics of the container and of its contents, means (53, 55) for obtaining at least one additional physical datum relating to a characteristic of the container (R), and means (50) capable of providing information relating to the nature of the contents of said container (R) depending on the measured complex impedance and on the additional physical datum

Abstract: A method for analyzing skin response waveform information obtained by measuring skin impedance with a voltage of a predetermined frequency. A current value at the start of polarization caused by the application of the voltage is determined, followed by determining a current value after a predetermined amount of time from the start of the polarization. A current value after termination of the polarization (value NT) is then determined and the difference between the current value at the start of the polarization and after the predetermined amount of time from the start of the polarization (value A) is determined. The difference between the current value after the predetermined amount of time from the start of the polarization and the value NT (value B) is determined, followed by analyzing the skin response waveform information using the ratios A/B, B/A and the value NT.

Abstract: A digital eddy current proximity system including a digital impedance measuring device for digitally measuring the proximity probes impedance correlative to displacement motion and position of a metallic target object being monitored. The system further including a cable-length calibration method, an automatic material identification and calibration method, a material insensitive method, an inductive ratio method and advanced sensing characteristics.

Abstract: A digital eddy current proximity system including a digital impedance measuring device for digitally measuring the proximity probes impedance correlative to displacement motion and position of a metallic target object being monitored. The system further including a cable-length calibration method, an automatic material identification and calibration method, a material insensitive method, an inductive ratio method and advanced sensing characteristics.

Abstract: A transducer calibration apparatus and method for transforming both previously established transducer parameters for a transducer calibrated to a first target object material and measured transducer parameters for the transducer monitoring a second different target object material into a calibration parameter and transforming the output of the transducer and thus, the use of the transducer, from the first target object material used to calibrate the transducer to the second different target object material being subsequently monitored by the transducer by linearizing the output of the transducer into gap values as a function of the calculated calibration parameter and then, generating alarms based on the linearized output of the transducer exceeding established limits and using the alarms to automatically shut down a machine being monitored by the transducer and/or automatically annunciate machine problems to personnel.

Abstract: A digital eddy current proximity system including a digital impedance measuring device for digitally measuring the proximity probes impedance correlative to displacement motion and position of a metallic target object being monitored. The system further including a cable-length calibration method, an automatic material identification and calibration method, a material insensitive method, an inductive ratio method and advanced sensing characteristics.

Abstract: A digital eddy current proximity system including a digital impedance measuring device for digitally measuring the proximity probes impedance correlative to displacement motion and position of a metallic target object being monitored. The system further including a cable-length calibration method, an automatic material identification and calibration method, a material insensitive method, an inductive ratio method and advanced sensing characteristics.

Abstract: Device for the ratiometric measurement of sensor signals using an analog/digital converter whose supply voltage is generated by means of a voltage controller, having an operational amplifier which is connected as a voltage follower and whose noninverting input is supplied with the sensor reference voltage and whose output is connected to the supply voltage input via a voltage divider whose tap is fed back to the inverting input of the voltage follower.

Abstract: An n-port network analyzer system is calibrated. An initial calibration is performed for each test port in the network analyzer system by first performing a measurement calibration using calibration standards. The calibration standards are located in a reference plane located outside the network analyzer system. The measurement calibration yields initial calibration coefficients. The initial calibration coefficients include Forward Load Match (LMF) and Reverse Load Match (LMR). Electronic standards are measured within the network analyzer system to: produce initial measured electronic standards. The initial calibration coefficients and the initial measured electronic standards are used to generate initial corrected electronic standards. After the initial calibration, automatic re-calibrations are performed periodically. When performing the automatic recalibration, the electronic standards within the network analyzer system are measured to produce recalibration measured electronic standards.

Abstract: A radio frequency network analyzer connected to a multi-port test set is calibrated. An initial calibration is performed for each test set port in the multi-port test set. The initial calibration is performed by first performing a measurement calibration using calibration standards. The calibration standards are located in a reference plane located outside the multi-port test set. The measurement calibration yields initial calibration coefficients. Also the initial calibration includes measuring electronic standards within the multi-port test set to produce initial measured electronic standards. The initial calibration coefficients and the measured electronic standards are used to generate initial corrected electronic standards.

Abstract: A ratiometric circuit (40) includes a differential capacitive sensor (42) for sensing a change in capacitance, a differential capacitive detector (46) operatively connected to the differential capacitive sensor for detecting a change in the capacitance of the differential capacitve sensor, an error voltage generator (48) operatively connected to the differential capacitve detector for generating a corrective voltage in response to the detected change in capacitance, and a bias circuit (50) operatively connected to the differential capacitive sensor for generating a bias voltage inversely proportional to and independent of a supply voltage for maintaining the ratiometricity between an output voltage of the differential capacitive sensor and the supply voltage.

Abstract: A ratiometric Fourier analyzer is provided for determining the frequency components of the output waveforms of electronic circuits by eliminating errors due to aliasing without increasing the time necessary for analysis. Ratiometric Fourier analyzers in accordance with the present invention detect values of an output waveform from a circuit simulator at time intervals selected according to features of the output waveform being analyzed. A functional representation of the output waveform over each interval is generated using a polynomial fit to the detected values of the waveform, and a Fourier integral for each frequency of interest is calculated for interval using the functional representation of the waveform. The Fourier integrals are then summed over the intervals of the output waveform to yield the Fourier coefficient at a given frequency for the output waveform.

Abstract: A ratiometric converter receives an external sense signal and external reference signal and provides an output signal which is proportional to the sense signal and inversely proportional to the reference signal. Electromagnetic interference and noise coupled onto the sense and reference lines are effectively removed by converting the sense signal to a digital signal and converting the reference signal to a digital signal. The digital sense signal is then filtered through a low pass filter to provide a filtered signal, and similarly, the digital reference signal is filtered through a low pass filter to provide a filtered digital reference signal. A divider circuit then divides the filter digital sense signal by the filter digital reference signal to provide the output signal.

Abstract: A portable device for use in the measurement of the dielectric properties of materials such as fish includes: a microwave circuit comprising a microwave source (10) connected via an isolator (12) to a directional coupler (14), a first output (16) of which is connected to a reference detector (18) and a first pre-amplifier (28) and a second output (20) of which is connected via an attenuator (22) to a sensor (24), an output of which is connected to a signal detector (26) and a second pre-amplifier (30); and further including two amplifiers (32, 34) into which outputs of the first (28) and second (30) pre-amplifiers are connected and a logarithmic/ratio device (38) which provides an output proportional to the logarithm of the ratio of outputs from the two amplifiers (32, 34), wherein an output from the logarithmic/ratio device (38) is calibrated to provide the content of a particular constituent of the material under test.

Abstract: A current comparator bridge for measuring the value of an unknown capacitor includes a current comparator having a first comparator winding with an adjustable tap which is connected to one side of a standard capacitor and a second comparator winding connected to one side of an unknown capacitor, a high voltage source being connected to the other side of the capacitors. The current comparator is provided with a detection winding for detecting when the ampere-turns in the first and second comparator windings are equal and opposed to each other. In addition to the current through the standard capacitor being applied to the first comparator winding, the bridge includes a circuit to add a current through a standard conductance to the first comparator winding as well as circuits to compensate for errors. The detection winding is connected to a current-to-voltage converter with an adjustable gain which provides a signal to a phase sensitive detector.

Abstract: A fuel composition sensor for a fuel line carrying a mixture of two fuels provides a fuel composition signal VOUT to an engine control computer having a computer analog reference voltage ECM referenced to a computer ground EGD. The sensor has a sensor analog reference voltage VREF referenced to a sensor ground GND, which may differ from the computer ground EGD. An input isolation amplifier derives the sensor analog reference voltage VREF relative to GND ratiometrically from the computer analog reference voltage ECM referenced to EGD; and an output isolation amplifier derives the fuel composition signal VOUT referenced to EGD ratiometrically from the difference between a fuel composition responsive sensor signal VSIG and its minimum possible value, corresponding to a sensed fuel composition of only one of the fuels, relative to GND. The sensor may comprise a capacitive voltage divider and provide sensor voltage VSIG also having a maximum value corresponding to a sensed fuel composition of only the other fuel.

Abstract: A transducer system and method of use thereof by sequentially operating a comparator to produce a series of pulses in which the time distribution of the pulses is representative of the transducer value, and is used to normalize the sensed value in the event that the total transducer value varies due to environmental influences. The transducer is adapted to monitor the substantially linear movement of the level (fuel-air interface) of fuel in a tank and the angular positon of an input shaft.

Abstract: A transducer system and method of use thereof by sequentially operating a comparator to produce a series of pulses in which the time distribution of the pulses is representative of the transducer value, and is used to normalize the sensed value in the event that the total transducer value varies due to environmental influences. The transducer is adapted to monitor the substantially linear movement of the level (fuel-air interface) of fuel in a tank and the angular position of an input shaft.

Abstract: A noise rejection circuit improves the signal-to-noise ratio of a ratiometric measurement circuit. A first operational amplifier produces a scaled-up voltage proportional to a low reference voltage. The scaled-up voltage is applied to a series connected reference resistance, whose value is known, and a resistance whose value is unknown and is to be measured. A parameter voltage formed across the resistance is applied to second operational amplifier acting as a buffer. A buffered parameter voltage is scaled down by a voltage divider. The scaled-down voltage is applied to a ratiometric converter, that produces an output representative of the unknown resistance value. The ratio of a first pair of resistors that determines the gain of the first operational amplifier is the same as the ratio of a second pair of resistors that form the voltage divider, such that the low reference voltage is scaled up and the parameter voltage is scaled down by the same factor.

Abstract: An impedance meter with improved measurement accuracy obtained by controlling the level of the signal source. The impedance meter comprises a signal source, feedback amplifier, synchronous detector, A/D and control logic. The source level is maintaind by the control logic at a predetermined value by measuring the output of a synchronous detector and intermittently adjusting the level of the source thereby compensating for variations in test object's impedance. Control logic algorithms employed include successive substitution, bisection and linear interpolation.

Abstract: In connection with a method and a device for processing measured values, where resistance variations are evaluated as a measure for the variation of the gas concentration to be measured, it is proposed to measure a basic resistance value at least once, preferably repeatedly, by admitting a standard calibration gas, and to store this resistance value and derive therefrom, for each subsequent measurement of the gas component the concentration of which is to be measured, by an arithmetic operation, the ratio between the resulting total resistance value and the momentary basic resistance value, and to evaluate the ratio so obtained for further processing.