Method for operating a measuring point

• US 9,164,057 B2
• Filed: 08/14/2009
• Issued: 10/20/2015
• Est. Priority Date: 09/05/2008
• Status: Active Grant

• Current Assignee: Endress + Hauser Conducta Gesellschaft Fur Mess- Und Regeltechnik Mbh + Co. Kg
• Original Assignee: Endress+Hauser GmbH+Co (ENDRESS)
• Inventors: Pechstein, Torsten, Scholz, Katrin, Trapp, Thilo, Grosse-Uhlmann, Ronny
• Primary Examiner(s): Lau, Tung S
• Assistant Examiner(s): SUN, XIUQIN
• Application Number:
  US12/461,528
• Publication Number:
  US 20100063762A1
• Time in Patent Office: 2,258 Days
• Field of Search: 702/34, 702/81, 702/82, 702/84, 702/85
• US Class Current: 1/1
• CPC Class Codes: G01N 27/4165 for pH meters

Abstract

A method for operating a measuring point for determining at least one measured variable of a medium is disclosed. The measuring point includes a base unit, which is connected releasably with a sensor unit, and which is provided for communication of a signal representing the value of the measured variable to a process monitoring facility. The following steps are included: at least one-time registering and storing in the base unit a value of a diagnostic parameter stored in the sensor unit or produced by the sensor unit; on the basis of this value conforming a prognosis value or prognosis interval stored in the base unit, and storing the conformed prognosis value or prognosis interval in the base unit in place of the previously stored prognosis value or prognosis interval.

Claims

1. A method for operating a measuring point for determining at least one measured variable of a medium, wherein the measuring point comprises a base unit, which is connected releasably with a first sensor unit, and which is provided for communication of a signal representing a value of the measured variable to a process monitoring facility, the method comprises steps of:

a) at least one-time registering and storing, in the base unit, a value of a diagnostic parameter stored in the first sensor unit or produced by the first sensor unit;

b) on the basis of said value of the diagnostic parameter stored in the base unit, conforming a prognosis value or prognosis interval stored in the base unit, said prognosis value being a prognosis value of said diagnostic parameter and said prognosis interval is a confidence interval surrounding the prognosis value; and

c) storing the conformed prognosis value or prognosis interval in the base unit in place of a previously stored prognosis value or prognosis interval, wherein;

the conforming of the prognosis value or prognosis interval occurring by means of a learning algorithm, which is embodied to learn, over the lifetime of a plurality of sensor units, said prognosis value or prognosis interval;

said diagnostic parameter is a total loading reserve, a total operating time, operating times under defined conditions or a counter state; and

said prognosis interval is a confidence interval surrounding the prognosis value;

wherein a counter state is one of;

a counter state for counting cleaning in process (CIP) steps, a counter state for counting sterilization in process (SIP) steps or a counter state for counting autoclaving steps.

2. The method as claimed in claim 1, further comprising a step of:

d) comparing the value of a diagnostic parameter registered in step a), stored in the base unit, or produced by the first sensor unit, with the prognosis value or prognosis interval stored in the base unit.

3. The method as claimed in claim 2, further comprising:

e) replacing the first sensor unit by a second sensor unit of the same type, and;

f) after replacement of the first sensor unit by the second sensor unit of the same type at least steps a) to (c) are repeated at least once.

4. The method as claimed in claim 3, wherein:

said first and second sensor units are pH-sensor units of the same type.

5. The method as claimed in claim 1, further comprising the step of:

e) replacing the first sensor unit by a second sensor unit of the same type and, after replacement of the first sensor unit by the second sensor unit of the same type, at least steps a) and b) are repeated at least once.

6. The method as claimed in claim 1, wherein:

the learning algorithm comprises a step of average forming, sliding weighted average forming, exponential smoothing of 1st and 2nd type, linear regression, matching of polynomials or matching of non-linear functions.

7. The method as claimed in claim 1, wherein:

at least one additional piece of information is made available to the base unit for ascertaining the prognosis value and;

said additional information comprising a weighting of said diagnostic parameter value.

8. The method as claimed in claim 1, wherein:

said value of said diagnostic parameter is stored in a first data storage unit of the base unit and said prognosis value or prognosis interval and said conformed prognosis value or said conformed prognosis interval are stored in a second data storage unit of the base unit; and

the first data storage unit comprises a memory unit having a plurality of memory locations, and wherein the value of the diagnostic parameter is stored in a memory location together with an identification of the associated sensor unit.

9. The method as claimed in claim 1, further comprising the step of:

d) registering as the diagnostic parameter a parameter related to sensor loading, and, storing as the prognosis value or prognosis interval a parameter, which correlates with a total sensor loading, with which the first sensor unit can be loaded before it must be replaced.

10. The method as claimed in claim 9, wherein:

periodically values of the diagnostic parameter which correlates with the sensor loading are registered one after the other and stored in the base unit.

11. The method as claimed in claim 10, wherein:

in the case of a defective sensor unit, an information, that the first sensor unit is replaced because of a defect, is made available to the base unit.

12. The method as claimed in claim 11, wherein:

after information that the sensor unit is replaced because of a defect has been made available, a last stored value of the parameter which correlates with the sensor loading currently stored in the base unit is used for conforming the stored prognosis value or prognosis interval.

13. The method as claimed in claim 10, further comprising:

e) comparing currently registered values of the diagnostic parameter with the stored prognosis value or prognosis interval.

14. The method as claimed in claim 13, wherein:

a warning message is generated, when one of the periodically registered values of the diagnostic parameter exceeds a lower limit of the prognosis interval stored in the base unit.

15. The method as claimed in claim 1, wherein:

values of a calibration parameter of the first sensor unit are repeatedly registered as values of said diagnostic parameter, and stored in individual locations of a data storage unit of the base unit, together with points in time of registering, or a parameter equivalent thereto, and an identification of the first sensor unit; and

as prognosis values, expected values of the calibration parameter of the first sensor unit at the points in time of registering are stored and conformed on the basis of the registered values of the calibration parameter.

16. The method as claimed in claim 15, wherein:

said first sensor unit is calibrated periodically, and with each new calibration, a value of said calibration parameter is registered and stored.

17. The method as claimed in claim 15, wherein:

the calibration parameter is one of;

sensor zero point, sensor slope, sensor zero point shifting or sensor slope shifting.

18. The method as claimed in claim 1, wherein:

said prognosis value or prognosis interval was ascertained from corresponding data of sensor units earlier applied at the measuring point.

19. The method according to claim 1, wherein:

said learning algorithm conforming the prognosis value by ascertaining the conformed prognosis value from said stored value of the diagnostic parameter and from corresponding values of the diagnostic parameter which were ascertained for sensor units earlier applied at the measuring point.

20. The method as claimed in claim 1, further comprising:

d) comparing currently registered values of the diagnostic parameter with the stored prognosis value or prognosis interval; and

e) depending on the position of the value of the diagnostic parameter with reference to the range of the prognosis interval, generating a warning or alarm message on a display of the base unit.

21. The method as claimed in claim 20, wherein:

the warning message is generated, when the value of the diagnostic parameter exceeds a lower limit of the prognosis interval.

22. A method for operating a measuring point for determining at least one measured variable of a medium, wherein the measuring point comprises a base unit, which is connected releasably with a first sensor unit, and which is provided for communication of a signal representing a value of the measured variable to a process monitoring facility, the method comprises steps of:

a) at least one-time registering and storing, in the base unit, a value of a diagnostic parameter stored in the first sensor unit or produced by the first sensor unit;

b) on the basis of said value of the diagnostic parameter stored in the base unit, conforming a prognosis value or prognosis interval stored in the base unit, said prognosis value being a prognosis value of said diagnostic parameter and said prognosis interval is a confidence interval surrounding the prognosis value;

c) storing the conformed prognosis value or prognosis interval in the base unit in place of a previously stored prognosis or prognosis interval;

d) registering as the diagnostic parameter a parameter related to sensor loading, and, storing as the prognosis value or prognosis interval a parameter, which correlates with a total sensor loading, with which the first sensor unit can be loaded before it must be replaced; and

e) comparing currently registered values of the diagnostic parameter with the stored prognosis value or prognosis interval, wherein;

the conforming of the prognosis value or the prognosis interval occurring by means of a learning algorithim, which is embodied to learn, over the lifetime of a plurality of sensor units, said prognosis value or prognosis interval;

periodically values of the diagostic parameter which correlates with the sensor loading are registered one after the other and stored in the base unit;

a warning message is generated, when one of the periodically registered values of the diagnostic parameter exceeds a lower limit of the prognosis interval stored in the base unit;

the parameter related to sensor loading is a weighted loading time of the sensor unit;

the parameter correlating with the total sensor loading, with which the sensor unit can be loaded is a total reserve; and

the prognosis interval is a confidence interval of the total loading reserve.

23. A method for operating a measuring point for determining at least one measured variable of a medium, wherein the measuring point comprises a base unit, which is connected releasably with a first sensor unit, and which is provided for communication of a signal representing a value of the measured variable to a process monitoring facilty, the method comprises steps of:

a) at least one-time registering and storing, in the base unit, a value of a diagnostic parameter stored in the first sensor unit or produced by the first sensor unit;

b) on the basis of said value of the diagnostic parameter stored in the base unit, conforming a prognosis value or prognosis interval stored in the base unit, said prognosis balue being a prognosis value of said diagnostic parameter and said prognosis interval is a confidence interval surrounding the prognosis value; and

c) storing the conformed prognosis value or prognosis interval in the base unit in place of a previously stored prognosis value or prognosis interval, wherein;

the conforming of the prognosis value or prognosis interval occurring by means of a learning algorithim, which is embodied to learn, over the lifetime of a plurality of sensor units, said prognosis value or prognosis interval;

values of a calibration parameter of the first sensor unit are repeatedly registered as values of said diagnostice parameter, and stored in individual location of a data storage unit of the base unit, together with points in time of registering, or a parameter equivalent thereto, and an identification of the first sensor unit;

as prognosis values, expected values of the calibration parameter of the first sensor unit at the pints in time of registering are stored and conformed on the basis of the registered values of the calibration parameter; and

as prognosis intervals a limit value window around the expected values of the calibration parameter are stored and conformed on the basis of the registered values of the calibration parameter.

24. The method as claimed in claim 23, further comprising:

d) comparing currently registered values of the calibration parameter with the stored prognosis values or prognosis intervals.

25. The method as claimed in claim 24, wherein:

a warning message is generated, when one of the periodically registered values of the diagnostic parameter exceeds a lower limit of the prognosis interval.