Calibrating an oxygen sensor of a domestic appliance

Patent metadata

Field	Value
Publication number	US-2020018721-A1
Application number	US-201716335273-A
Country	US
Kind code	A1
Filing date	Nov 2, 2017
Priority date	Nov 2, 2016
Publication date	Jan 16, 2020
Grant date	—

Abstract

A method for calibrating an oxygen sensor of a household appliance includes a calibration process which is automatically started when at least one status parameter of the household appliance has at least reached a predetermined threshold value. The household appliance can be a steam cooking appliance, and the oxygen sensor can be a lambda probe.

First claim

1 - 15 . (canceled)

16 . A method, comprising:
starting a calibration process for calibrating an oxygen sensor of a household appliance when a status parameter of the household appliance has at least reached a predetermined threshold value.

17 . The method of claim 16 , wherein the household appliance is a steam cooking appliance.

18 . The method of claim 16 , wherein the oxygen sensor is a lambda probe.

19 . The method of claim 16 , wherein the calibration process is automatically started when a plurality of status parameters of the household appliance have reached predetermined threshold values, respectively.

20 . The method of claim 16 , wherein the status parameter comprises a time period elapsing since a last calibration and the calibration process is automatically started when the time period has reached or exceeded the threshold value.

21 . The method of claim 16 , wherein the status parameter comprises a door opening time and the calibration process is automatically started when the door opening time has reached or exceeded the threshold value.

22 . The method of claim 16 , wherein the status parameter comprises a cooking chamber temperature and the calibration process is automatically started when the cooking chamber temperature has reached or fallen below the threshold value.

23 . The method of claim 18 , further comprising:
measuring during the calibration process a pump flow of the lambda probe; and when the pump flow remains for a predetermined time period within a predetermined fluctuation margin, selecting a value of the pump flow from the fluctuation margin as a reference value of the pump flow.

24 . The method of claim 23 , wherein an average value of the fluctuation margin is selected as the reference value of the pump flow.

25 . The method of claim 16 , further comprising discontinuing the calibration process when the calibration process lasts longer than a predetermined threshold value.

26 . The method of claim 16 , further comprising discontinuing the calibration process when a cooking chamber door of the household appliance is closed.

27 . The method of claim 16 , further comprising:
storing a result of the calibration process; and evaluating the result for a malfunction of the oxygen sensor.

28 . The method of claim 27 , further comprising:
measuring during the calibration process a pump flow of the lambda probe; when the pump flow remains for a predetermined time period within a predetermined fluctuation margin, selecting a value of the pump flow from the fluctuation margin as a reference value of the pump flow; and using the reference value of the pump flow as the result.

29 . A household appliance, comprising:
a treatment chamber; an oxygen sensor; and a data processing device for determining a moisture content in the treatment chamber based on a measured value of the oxygen sensor, said household appliance being configured to start a calibration process for calibrating the measured value of the oxygen sensor when a status parameter of the household appliance has at least reached a predetermined threshold value.

30 . The household appliance of claim 29 , wherein the household appliance is a steam cooking appliance, with the treatment chamber representing a cooking chamber configured for application of steam.

31 . The household appliance of claim 29 , wherein the oxygen sensor is a lambda probe.

32 . The household appliance of claim 30 , wherein the status parameter comprises a temperature in the cooking chamber temperature, with the calibration process being automatically started when the temperature in the cooking chamber has reached or fallen below the threshold value.

33 . The household appliance of claim 30 , further comprising a door for opening and closing the cooking chamber, wherein the status parameter comprises an opening time of the door, with the calibration process being automatically started when the opening time of the door has reached or exceeded the threshold value.

34 . The household appliance of claim 29 , wherein the data processing device includes a memory device configured to store a result of the calibration process.

Assignees

• Bsh Hausgeraete Gmbh

Inventors

• Lego Dieter
• BAUER HANS-JüRGEN

Classifications

• F24C7/08

  Arrangement or mounting of control or safety devices · CPC title

• G01N27/407

  for investigating or analysing gases {(G01N27/411 takes precedence)} · CPC title

• A47J2027/043

  for cooking food in steam · CPC title

• F24C15/003

  moisturising of air · CPC title

• G01N27/4175 Primary

  Calibrating or checking the analyser · CPC title