In a meter for performing a measurement of an electrical parameter, an output from a sensor is sampled to produce at least one sample, and an iterative method is performed comprising: producing further samples; holding in memory a stored array of samples comprising the at least one sample and each of the further samples from each iteration; determining a measure of statistical variability of a mean for the respective iteration from a measure of statistical variability and from the number of samples used to generate the measure of statistical variability; comparing the measure of statistical variability of the mean with a pre-determined threshold; and generating an electrical signal indicating a state of the measurement if the measure of statistical variability of the mean of the samples taken during the measurement is less than or equal to the pre-determined threshold.

In a meter for performing a measurement of an electrical parameter, an output from a sensor is sampled to produce at least one sample, and an iterative method is performed comprising: producing further samples; holding in memory a stored array of samples comprising the at least one sample and each of the further samples from each iteration; determining a measure of statistical variability of a mean for the respective iteration from a measure of statistical variability and from the number of samples used to generate the measure of statistical variability; comparing the measure of statistical variability of the mean with a pre-determined threshold; and generating an electrical signal indicating a state of the measurement if the measure of statistical variability of the mean of the samples taken during the measurement is less than or equal to the pre-determined threshold.

Provided is a device or the like that can improve the accuracy of battery performance evaluation of a rechargeable battery. Parameter values of a rechargeable battery model are identified on the basis of a measurement result of a complex impedance Z of a first rechargeable battery 221. The rechargeable battery model expresses an impedance of an internal resistance of the first rechargeable battery 221 with transfer functions representing IIR and FIR systems, respectively. Performance of a second rechargeable battery 222 is evaluated on the basis of a result of contrast between a voltage response characteristic V(t) that is output from a rechargeable battery 220 as the second rechargeable battery 222 when an impulse current I(t) is input to the second rechargeable battery 222, and a model voltage response characteristic V.sub.model(t) when the impulse current is input to the rechargeable battery model having the parameter values identified.

Circuitry comprising: a voltage monitoring path; a current monitoring path; a reference element of a predefined impedance; and processing circuitry, wherein in operation of the circuitry in a calibration mode of operation: the voltage monitoring path is operative to output a signal indicative of a voltage across the reference element in response to a reference signal applied to the reference element; the current monitoring path is operative to output a signal indicative of a current through the reference element in response to the reference signal; and the processing circuitry is operative to: receive the signal indicative of the voltage across the reference element and the signal indicative of the current through the reference element; generate an estimate of an impedance of the reference element; and determine a compensation parameter for an element of the circuitry for compensating for a difference between the estimate of the impedance and the predefined impedance of the reference element.

Circuitry comprising: a voltage monitoring path; a current monitoring path; a reference element of a predefined impedance; and processing circuitry, wherein in operation of the circuitry in a calibration mode of operation: the voltage monitoring path is operative to output a signal indicative of a voltage across the reference element in response to a reference signal applied to the reference element; the current monitoring path is operative to output a signal indicative of a current through the reference element in response to the reference signal; and the processing circuitry is operative to: receive the signal indicative of the voltage across the reference element and the signal indicative of the current through the reference element; generate an estimate of an impedance of the reference element; and determine a compensation parameter for an element of the circuitry for compensating for a difference between the estimate of the impedance and the predefined impedance of the reference element.

Kelvin (4-wire) connecting cables are routinely used when performing dynamic measurements (i.e., measurements with time-varying signals) on electrochemical cells and batteries. Current-carrying and voltage-sensing conductor pairs within such cables comprise distributed-parameter two-wire transmission lines which may extend several meters in length. As with all such transmission lines, internally reflected waves can oscillate back and forth at high frequency (hf) whenever the lines are not terminated in their characteristic impedances. Such hf reflected waves, by interacting with measuring circuitry, can seriously degrade low-frequency measurement accuracy. Apparatus is disclosed herein that suppresses hf reflected waves oscillating on Kelvin connecting cables during dynamic measurements of cells and batteries.

[Problem to be Solved]

The present invention provides a system which can detect/check an underground water vein in a specific ground area and detect/check underground water in the underground water vein at a pinpoint.

[Solution]

The present invention has, while two-dimensionally visualizing an underground water vein in a specific ground area, a large number of electrodes group 22 disposed in the specific ground area, a survey point switching unit 23 having two poles in an electrode 22a with four poles in dipole-dipole arrangement in the electrodes group 22 set to potential electrodes, while the other two poles as current electrodes and combining and switching them so as to execute horizontal exploration and underground vertical exploration, measuring means 25 for each survey point of the entire ground area, specific resistance calculating means 31 for each survey point for calculating a specific resistance value at each survey point for each of high and low two frequencies in the horizontal and vertical directions at each survey point of the ground area, and impedance effect is acquired for each survey point on the basis of the calculated specific resistance value for each of the high and low two frequencies at each survey point so that estimation that a survey point position with the impedance effect>1 has an underground water vein can be made and displayed three-dimensionally.

A resistance measurement system can include a plurality of resistors connected in series along a single line. The plurality of resistors can include N resistors. The system can include a plurality of capacitors for at least N−1 of the resistors. Each capacitor can be connected in parallel to the single line with a respective resistor to form a respective resistor-capacitor (RC) pair. Each RC pair can include a different time constant such that each RC pair reaches a steady state voltage at a different time. The system can include a current supply connected to the single line to supply a current to the line. The system can include a control module configured to sense a total voltage across the single line and to successively determine resistance of each resistor from the total voltage based on the current, a known total steady state voltage, and known time-to-steady-state-voltages of each RC pair and/or resistors.

An electrostatic encoder (40) detects the rotation angle of a rotor (42) with great accuracy based on the change in the capacitance between electrodes arranged on a stator (41) and the rotor (42). Detection electrodes (44a to 44d) and transmission electrodes (45a to 45d) are arranged circumferentially and alternately on the stator (41). Detection signals (phase A, phase B) amplitude-modulated based on the rotation of the rotor (42) and having a mutual phase difference of 90 degrees are output from adjacent ones of the detection electrodes. Modulated signals (V1, V2) are generated by demodulating the detection signals having a mutual phase difference of 90 degrees. Applying resolver-digital (RD) conversion processing to the modulated signals allows obtaining the rotation angle of the rotor.

A household PEF cooking appliance includes a cooking product container fillable with liquid and cooking product and including, on its inner faces, a plurality of mutually insulated electrodes. An excitation device supplies at least two of the plurality of electrodes with pulsed electric signals, and a resistance measuring device applies a measuring signal to at least two of the plurality of the electrodes in order to measure an associated current signal and to determine a resistance value of a content of the cooking product container. A control device operates the excitation device and the resistance measuring device separately and operates the excitation device based on the resistance value.