# US 10,871,540 B2 · Measurement device and method for measuring current calibration coefficient, and current detection device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,871,540 B2 - Document ID: US10871540B2 - Status: Granted - Kind: B2 - Application number: 16/165,801 - Filed: 2018-10-19 - Published: 2019-04-25 - Granted: 2020-12-22 - Earliest claimed: 2017-10-23 - Assignees: Contemporary Amperex Technology Co., Limited - Applicants: Contemporary Amperex Technology Co., Limited - Inventors: Yizhen Hou; Zhimin Dan; Wei Zhang; Jia Xu - Web page: https://patentgrep.com/patent/US10871540B2 ## CPC - G01R 35/005: {Calibrating; Standards or reference devices, e.g. voltage or resistance standards, "golden" references (G01R33/0035, G01R35/002 take precedence)} - G01R 1/203: {Resistors used for electric measuring, e.g. decade resistors standards, resistors for comparators, series resistors, shunts (resistors in general H01C; microwave or radiowave terminations H01P1/26; coupling devices H01R)} - G01R 19/25: using digital measurement techniques - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## Abstract A measurement device for measuring a current calibration coefficient includes: a host computer and a current source, wherein the host computer is configured to acquire current calibration coefficients including a current calibration coefficient at a temperature T1 and a current calibration coefficient at a temperature T2, and transmit the current calibration coefficients to the current detection device. The current calibration coefficients are acquired by: controlling the current source to output a first current with a first specified current value to the current detection device when ambient temperature of the current detection device is at the T1, calculating, according to the first specified current value and a first detected current value detected by the current detection device, a current calibration coefficient at the T1, and determining, according to the current calibration coefficient at the T1 and the resistance-temperature characteristic curve of the shunt, the current calibration coefficient at the T2. ## Claims ### Claim 1 A measurement device for measuring a current calibration coefficient, comprising a host computer; and a current source, wherein the host compute is configured to: acquire current calibration coefficients, wherein the current calibration coefficients comprises a current calibration coefficient at a temperature T1 and a current calibration coefficient at a temperature T2, wherein the T1 is a reference temperature of a resistance-temperature characteristic curve of a shunt of a current detection device, and the T2 is any one temperature other than the T1 within an operation temperature range of the shunt; and transmit the current calibration coefficients to the current detection device, wherein the current detection device is used for performing a detection of a current in a current circuit requiring current detection; wherein the current calibration coefficients are acquired by: controlling the current source to output a first current with a first specified current value to the current detection device when ambient temperature of the current detection device is at the T1, calculating, according to the first specified current value and a first detected current value detected by the current detection device in the current circuit, a current calibration coefficient at the T1, and determining, according to the current calibration coefficient at the T1 and the resistance-temperature characteristic curve of the shunt, the current calibration coefficient at the T2. ### Claim 2 (depends on 1) The measurement device according to claim 1, wherein the host compute is configured to: control the current source to sequentially output currents with n different first specified current values at the T1, acquire n first detected current values corresponding to the n different first specified current values, wherein n≥2; and calculate the current calibration coefficient at the T1 according to the n different first specified current values and the n first detected current values. ### Claim 3 (depends on 2) The measurement device according to claim 2, wherein the host compute is configured to calculate, according to the n different first specified current values and the n first detected current values, the current calibration coefficient at the T1 by a least-square linear fitting method, and wherein the current calibration coefficient comprises a linear calibration coefficient and a constant calibration coefficient. ### Claim 4 (depends on 3) The measurement device according to claim 3, wherein the host compute is configured to: determine a third actual resistance value R3 of the shunt at T2 according to T2 and the resistance-temperature characteristic curve, and calculate the current calibration coefficient at the T2 according to the R3 and the current calibration coefficient at the T1 by a formula: A3=A1*R3/R1,B3=B1 where A1 is the linear calibration coefficient at the T1, A3 is a linear calibration coefficient at the T2, B1 is the constant calibration coefficient at the T1, and B3 is a constant calibration coefficient at the T2. ### Claim 5 (depends on 1) The measurement device according to claim 1, wherein the host compute is further configured to: control the current source to output a current with a second specified current value when the ambient temperature of the current detection device is at the T2, acquire a second detected current value at the T2 detected by the current detection device, calculate a first actual resistance value R1 of the shunt at the T1 according to the first specified current value, the first detected current value at the T1 and a nominal resistance value of the shunt, calculate a second actual resistance value R2 of the shunt at the T2 according to the second specified current value, the second detected current value at the T2 and the nominal resistance value of the shunt, calculate, a resistance-temperature coefficient of the shunt at the T2 according to the R1 and R2, and determine the resistance-temperature characteristic curve of the shunt based on the resistance-temperature coefficient at the T2 and a resistance-temperature coefficient at the T1, wherein the resistance-temperature coefficient at the T1 is zero. ### Claim 6 (depends on 1) The measurement device according to claim 1, wherein the host compute is further configured to: control, when ambient temperature of the current detection device is at a preset temperature within the operation temperature range of the shunt, the current source to output a current with a preset current value, receive a calibrated current value sent by the current detection device, wherein the calibrated current value is obtained by calibration of a detected current value detected by the current detection device and corresponding to the preset current value with a predetermined current calibration coefficient for the preset temperature, calculate a measurement error of the current detection device according to the preset current value and the calibrated current value, and determine, if the measurement error is less than a preset current error, the predetermined current calibration coefficient as a current calibration coefficient of the current detection device for the preset temperature. ### Claim 7 (depends on 1) The measurement device according to claim 1, wherein the host compute is further configured to control the current source to output a first actual current value corresponding to the first specified current value; and calculate, according to the first detected current value and the first actual current value corresponding to the first specified current value, the current calibration coefficient at the T1 of the current detection device.