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EP-4742129-A1 - METHOD FOR CALIBRATING AND/OR ADJUSTING SENSORS USED IN PROCESS TECHNOLOGY

EP4742129A1EP 4742129 A1EP4742129 A1EP 4742129A1EP-4742129-A1

Abstract

The invention relates to a method for calibrating and/or adjusting process engineering sensors, comprising the following steps: Ordering a calibration by the customer, specifying the sensor's serial number; transmitting a digital calibration authorization and, optionally, calibration standards to the customer; performing and documenting the measurements by the customer, preferably supported by an app or instructions; transmitting the measured values and other necessary data to the manufacturer; checking the data by the manufacturer and issuing a calibration certificate, which is available at least digitally, but preferably also as a physical copy; and cryptographically linking the calibration certificates.

Inventors

  • SCHNEIDER, CHRISTIAN

Assignees

  • ifm electronic gmbh

Dates

Publication Date
20260513
Application Date
20251105

Claims (12)

  1. Methods for calibrating and/or adjusting sensors in process engineering, comprising the following steps: ▪ Ordering a calibration by the user 105) specifying the serial number 111) of the sensor 100) at the manufacturer's shop backend system 300); ▪ Transmission of a digital calibration authorization 315) and - unless this is in the possession of the customer or is an integral part of the sensor 100) - of a calibration standard 500) from the manufacturer's storage and shipping system 410) to the user 105); ▪ Performance and documentation of measurements using the calibration standards 500) by the user 105); ▪ Transfer of the measured values determined during calibration 121) to the manufacturer's shop backend system 300); ▪ Verification of the data by the manufacturer's shop backend system 300) and issuance of a calibration certificate 420), which is digitally stored in the sensor 100); ▪ Cryptographic linking of the calibration certificates 420).
  2. Method according to claim 1, characterized by the fact that the step of ordering includes a calibration: ▪ Generating a calibration request 110) by the field device 100), which contains the serial number 111) and a unique device ID UUID) 112) of the device 100) S2); ▪ Signing the calibration request 110) by the field device 100) using a device private key 101) S3) to generate a signed calibration request 115); ▪ Reading the signed calibration request 115) from the device 100) S4) and transmitting it together with an order 310) to the manufacturer's shop backend system 300).
  3. Method according to claim 2, characterized by the fact that the step includes the transmission of a digital calibration authorization: ▪ Verification of the legitimacy of the signed calibration request 115) by the manufacturer's shop backend system 300) using a device public key 102) of the device 100) S6); ▪ Signing the calibration request 110) by the manufacturer's shop backend system 300) using a shop private key 301) S8), in order to generate a signed calibration request 315); ▪ Transmission of the calibration request 315) signed by the manufacturer's shop backend system 300) to the field device 100) S11); ▪ Verification of the signature of the calibration request 315) signed by the manufacturer's shop backend system 300) by the field device 100) using a shop public key 302) S12) stored in the field device 100).
  4. Method according to any one of claims 1 to 3, characterized by the fact that the step includes carrying out and documenting the measurements: ▪ Checking the device status Z1) by the field device 100) for suitability for calibration S14); ▪ Packaging the determined measured values 121) into a digital measurement protocol 120) S16); ▪ Signing the digital measurement protocol 120) by the field device 100) using the device private key 101) S17) to generate a signed measurement protocol 125).
  5. Method according to claim 4, characterized by the fact that the step includes checking the data and issuing a calibration certificate: ▪ Transmission of the digital measurement protocol 125) signed by the field device 100) to a calibration laboratory of the manufacturer 400) S19); ▪ Evaluation of the digital measurement protocol 125) by the manufacturer's calibration laboratory 400); ▪ Signing of the digital measurement protocol 125) by the manufacturer's calibration laboratory 400) using a laboratory private key 401) S21), thereby creating a digital calibration certificate 420); ▪ Transmission of the signed digital calibration certificate 420) to the field device 100) S22), where it is stored S23).
  6. Method according to claim 5, characterized in that the field device 100) enters a "calibrated" state Z2) after receiving the signed digital calibration certificate 420).
  7. Method according to any one of claims 1 to 6, characterized by the fact that the performance of the measurements by the user 105) is supported by an app or instructions on a website.
  8. Method according to any one of claims 1 to 7, characterized in that the transmission of the digital calibration authorization 315) and the calibration certificates 420) is carried out by means of any digital communication, in particular by scanning a QR code displayed on the screen.
  9. Method according to any one of claims 1 to 8, characterized in that, during calibration, in addition to the measured values 121), local environmental data from the location of the calibration are also transmitted to the manufacturer's shop backend system 300).
  10. Method according to any one of claims 1 to 9, characterized by the fact that adjustment data 421) together with the calibration certificate 420) are loaded into the sensor 100).
  11. Method according to any one of claims 1 to 10, characterized by the fact that the calibration certificate 420) is available both as a physical copy 425) and digitally.
  12. Method according to any one of claims 1 to 11, characterized by the fact that the cryptographic chaining of the Calibration certificates (420) enable complete documentation during audits.

Description

The invention relates to a method for calibrating and/or adjusting sensors in process engineering, which makes it possible to carry out these tasks on site by the operator himself. Conventional methods require that the sensors either be sent to a calibration laboratory or that a manufacturer's representative perform the calibration on-site. Both methods are complex and expensive and may potentially necessitate machine downtime. From the document WO 2023/117341 A1 A secure method for self-calibration or self-re-calibration of devices, in particular measuring instruments, by the operator is known, wherein a digitized process flow in a data chain (DLT), in particular blockchain, which is created and secured using a distributed ledger technology, is used. The document CN102291278A This describes a system and procedure for the remote testing, calibration, and maintenance of sensors or devices. The system includes sensors or devices, standard equipment, data acquisition modules, data writing modules, clients, and a remote service platform. The system aims to provide remote testing and calibration services for sensors or devices, as well as regular maintenance services for sensor or device products. The document WO2014/198564A1 describes a procedure for calibrating a sensor, comprising: determining a position of the sensor; providing sensor data, including identification data and the position of the sensor, to a calibration data provider; obtaining calibration data from the calibration data provider; and calibrating the sensor according to the calibration data. The document WO2016/094946A1 Describes a method, a system, a server, and a computer program product for calibrating a building sensor. In particular, the method may include: receiving sensor identification data at the computer system, wherein the identification data is provided by communicating an identifier that is assigned to the sensor and a The computer system is assigned an identification device configured to communicate with the system; it receives measurement data representing a physical phenomenon measured by a calibration sensor device, provided by communication between a portable calibration sensor device and an environment near the sensor, the portable calibration sensor device being configured to communicate with the system; it receives sensor data associated with the sensor's identification data, the sensor data representing a physical phenomenon provided by the sensor and measured by the sensor; and it calculates a difference value in the computer system between the measurement data and the sensor data to provide calibration data. The object of the invention is to simplify the calibration and/or adjustment of sensors in process engineering while ensuring reliable traceability. The problem is solved according to the invention by a method having the features of claim 1. Advantageous embodiments of the invention are specified in the dependent claims. The invention is explained in more detail below with reference to the accompanying drawings. These show: Figure 1 a schematic flowchart of the process flow for calibration request and release; Figure 2 a schematic flowchart of the process flow for calibration measurement and certificate creation. The method according to the invention begins with the user 105 ordering a calibration, specifying the serial number 111 of the sensor or field device 100 to be calibrated. This can be done via a user interface 200, for example an app on a mobile device or a website. Calibration request and approval process (see Fig. 1 ): First, user 105 executes a "Request calibration" function on field device 100, S1. Field device 100 then creates a calibration request 110, which includes the serial number 111 of device 100 and a unique device ID (UUID). 112 contains S2. This calibration request 110 is signed by the field device 100 using its device private key 101, S3, resulting in a signed calibration request 115. The user 105 reads the signed calibration request 115 from the field device 100, S4, via the user interface 200 and transmits it together with an order 310 for the digital service to the shop backend system of the manufacturer 300, S5. The manufacturer's shop backend system 300 verifies the legitimacy of the signed calibration request 115 by verifying the signature with the device public key 102 of device 100, S6. This device public key 102 was stored in a database 303 of the shop backend system 300 during the production of the field device 100. The shop backend system 300 also verifies the payment for the order, S7. After successful verification, the manufacturer's shop backend system 300 signs the calibration request 110 with its own shop private key 301, S8. This generates a digital calibration authorization in the form of a signed calibration request 315. This grants the authorization to execute the calibration function. Since the calibration request 110 is permanently linked to device 100 via the device p