Dynamic temperature compensation method for a turbidity sensor used in an appliance for washing articles

• US 5,555,583 A
• Filed: 02/10/1995
• Issued: 09/17/1996
• Est. Priority Date: 02/10/1995
• Status: Expired due to Fees

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Berkcan, Ertugrul
• Primary Examiner(s): Stinson, Frankie L.
• Application Number:
  US08/386,382
• Time in Patent Office: 585 Days
• Field of Search: 134/57 D, 134/58 D, 134/113, 68/12.02, 8/159, 8/158, 340/619, 250/564, 250/565, 356/436, 356/441, 356/442
• US Class Current: 8/158
• CPC Class Codes: A47L 15/4297 Arrangements for detecting or measuring the condition of the washing water, e.g. turbidity
• CPC Class Codes: D06F 2103/16 Washing liquid temperature
• CPC Class Codes: D06F 2103/20 Washing liquid condition, e.g. turbidity
• CPC Class Codes: D06F 34/22 Condition of the washing liquid, e.g. turbidity

Abstract

A dynamic temperature compensation method for a turbidity sensor in an appliance for washing articles is provided. The method includes the steps of: retaining substantially particle-free liquid upon completion of cleansing operations in the appliance, reading initial values of temperature and turbidity of the liquid, measuring additional values of temperature and turbidity of the liquid at predetermined time intervals, and calculating a temperature coefficient, based upon respective ones of the initial and the additional values of temperature and turbidity, for characterizing a temperature response of the turbidity sensor over a predetermined temperature range.

Claims

1. A dynamic temperature compensation method for a turbidity sensor used in an appliance for cleansing articles, said method comprising:

retaining substantially particle-free liquid upon completion of cleansing operations in said appliance;

reading initial values of temperature and turbidity of said liquid;

measuring additional values of temperature and turbidity of said liquid at predetermined time intervals; and

calculating a temperature coefficient, based upon respective ones of said initial and additional values of temperature and turbidity, for characterizing a temperature response of said turbidity sensor over a predetermined temperature range.

2. The dynamic temperature compensation method of claim 1 and further comprising the step of verifying that said appliance has not resumed cleansing operations while measuring each additional value of temperature and turbidity.

3. The dynamic temperature compensation method of claim 2 wherein the step of measuring the additional values of temperature and turbidity comprises the step of storing each last-measured value of temperature and turbidity whenever a temperature change sensed between the last-measured temperature value and the temperature value measured preceding the last-measured temperature value exceeds a predetermined threshold temperature.

4. The dynamic temperature compensation method of claim 3 wherein the step of measuring the additional values of temperature and turbidity further comprises the step of pausing for an additional time interval whenever the temperature change sensed between the last-measured temperature value and the temperature value measured preceding the last-measured temperature value is below the predetermined threshold temperature.

5. The dynamic temperature compensation method of claim 4 further comprising the step of counting the number of stored values of temperature and turbidity.

6. The dynamic temperature compensation method of claim 5 wherein the step of calculating said temperature coefficient is executed when the count number for the stored values of temperature and turbidity reaches a predetermined value.

7. The dynamic temperature compensation method of claim 6 further comprising the step of storing the calculated temperature coefficient so that turbidity values measured upon said appliance resuming cleansing operations can be adjusted based on the stored temperature coefficient to provide temperature compensated turbidity values.