# US 11,906,554 B2 · Meter for measuring an electrical parameter > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,906,554 B2 - Document ID: US11906554B2 - Status: Granted - Kind: B2 - Application number: 18/078,426 - Filed: 2022-12-09 - Published: 2023-04-06 - Granted: 2024-02-20 - Earliest claimed: 2017-05-16 - Assignees: Megger Instruments Limited - Applicants: Megger Instruments Ltd. - Inventors: Stanislaw Zurek; Jeffrey Jones - Web page: https://patentgrep.com/patent/US11906554B2 ## CPC - G01R 19/003: {Measuring mean values of current or voltage during a given time interval} - G01R 19/165: Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values - G01R 19/16504: {characterised by the components employed} - G01R 19/16566: {Circuits and arrangements for comparing voltage or current with one or several thresholds and for indicating the result not covered by subgroups G01R19/16504, G01R19/16528, G01R19/16533} - G01R 27/14: Measuring resistance by measuring current or voltage obtained from a reference source (G01R27/16, G01R27/20, G01R27/22 take precedence) - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## Abstract 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. ## Claims ### Claim 1 A method of operation of a meter for performing a measurement of an electrical parameter, the method comprising, in the meter: sampling an output from a sensor of the electrical parameter to produce at least one sample; and iteratively performing steps of: sampling the output from the sensor to produce one or more further samples; processing the at least one sample and each of the one or more further samples to generate a plurality of processed samples; holding in memory a stored array of processed samples for each iteration; determining a measure of statistical variability from the stored array of processed samples for the respective iteration; determining a measure of statistical variability of a mean of the processed samples for the respective iteration from the 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 of the processed samples 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 processed samples is less than or equal to the pre-determined threshold, wherein said processing comprises processing the at least one sample and each of the one or more further samples to derive a curve describing a trend and each processed sample represents a difference between the respective sample and the curve. ### Claim 2 (depends on 1) A method according to claim 1, wherein the electrical signal indicating a state of the measurement indicates that the measurement has reached or exceeded a target confidence level. ### Claim 3 (depends on 1) A method according to claim 1, wherein the electrical signal indicating a state of the measurement indicates that the measurement is complete. ### Claim 4 (depends on 1) A method according to claim 1, wherein the measure of statistical variability is a standard deviation. ### Claim 5 (depends on 1) A method according to claim 1, wherein the measure of statistical variability is a variance. ### Claim 6 (depends on 1) A method according to claim 1, wherein the measure of statistical variability of the mean is a standard deviation divided by the square root of the number of samples used to generate the measure of statistical variability. ### Claim 7 (depends on 1) A method according to claim 1, wherein determining the measure of statistical variability from the stored array of processed samples comprises, at each iteration: forming a second array of processed samples to be held for the iteration in addition to the stored array of processed samples by filtering the array of processed samples, and calculating the measure of statistical variability of the second array of processed samples. ### Claim 8 (depends on 7) A method according to claim 7, wherein filtering the stored array of processed samples comprises applying a median filter. ### Claim 9 (depends on 8) A method according to claim 8, wherein applying the median filter comprises: arranging the samples in the stored array of processed samples in order of magnitude; forming the second array of processed samples from the stored array of processed samples by discarding at least a sample with greatest magnitude. ### Claim 10 (depends on 9) A method according to claim 9, wherein forming the second array of processed samples from the stored array of processed samples comprises discarding a sample with greatest magnitude and a sample with least magnitude. ### Claim 11 (depends on 7) A method according to claim 7, comprising: calculating an average measurement of the electrical parameter at each iteration from the second array of processed samples; and generating an output indicating the average measurement. ### Claim 12 (depends on 1) A method according to claim 1, comprising: generating an output indicating confidence of the measurement at each iteration from the measure of statistical variability of the mean and a target measure of statistical variability of the mean. ### Claim 13 (depends on 12) A method according to claim 12, wherein the output indicating confidence of the measurement represents a percentage of a target confidence level. ### Claim 14 (depends on 1) A method according to claim 1, comprising: determining a time-to-finish estimate for the measurement from the measure of statistical variability; and generating an output indicating the determined time-to-finish estimate. ### Claim 15 (depends on 14) A method according to claim 14, wherein generating the output indicating the determined updated time-to-finish estimate comprises: calculating an average of said determined time-to-finish estimate and at least some of previously determined time-to-finish estimates. ### Claim 16 (depends on 1) A method according to claim 1, comprising stopping the measurement in response to the electrical signal indicating a state of the measurement. ### Claim 17 A meter for performing a measurement of an electrical parameter, comprising: a sensor configured to measure the electrical parameter; a processor configured to cause the meter to: sample an output from a sensor of the electrical parameter to produce at least one sample; and iteratively perform steps of: sampling the output from the sensor to produce one or more further samples; processing the at least one sample and each of the one or more further samples to generate a plurality of processed samples; holding in memory a stored array of processed samples for each iteration; determining a measure of statistical variability from the stored array of processed samples for the respective iteration; determining a measure of statistical variability of a mean of the processed samples for the respective iteration from the 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 of the processed samples 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 processed samples is less than or equal to the pre-determined threshold, wherein said processing comprises processing the at least one sample and each of the one or more further samples to derive a curve describing a trend and each processed sample represents a difference between the respective sample and the curve. ### Claim 18 (depends on 17) The meter of claim 17, wherein the electrical signal indicating a state of the measurement indicates that the measurement has reached or exceeded a target confidence level or indicates that the measurement is complete.