Process and device for measuring the state of degradation of oils or fats

• US 6,822,461 B2
• Filed: 12/27/2002
• Issued: 11/23/2004
• Est. Priority Date: 12/28/2001
• Status: Expired due to Term

• Current Assignee: Xylem Analytics Germany GmbH (Xylem, Inc.)
• Original Assignee: EBRO Electronic GmbH & Co. KG (Xylem, Inc.)
• Inventors: Klün, Wolfgang
• Primary Examiner(s): Deb, Anjan
• Assistant Examiner(s): Benson, Walter
• Application Number:
  US10/330,451
• Publication Number:
  US 20030155935A1
• Time in Patent Office: 697 Days
• Field of Search: 73/530.2, 324/71.1, 324/664, 324/698, 436/60
• US Class Current: 324/698
• CPC Class Codes: G01N 27/221 by investigating the dielectric properties using microwaves G01N22/00; measuring loss factors or dielectric constants per se G01R27/26
• CPC Class Codes: G01N 27/226 Construction of measuring vessels; Electrodes therefor
• CPC Class Codes: G01N 33/03 Edible oils or edible fats

Abstract

The present invention relates to a process and device for the monitoring of fats and oils in the preparation of food, which provide for the exchange of oil or fat in a timely manner, before they have become harmful for human consumption. The proposed process for measurement distinguishes itself by the fact that the measurement is already taking place during the temperature adaptation of the sensor, whereby a measurement can take place which is particularly fast and thus suitable for use in practice. Along with this, the device is formed in such a manner that disturbances of the measurement can be largely eliminated.

Claims

1. A device for measuring the state of degradation of oil and fat comprising:

a carrier,

a sensor mounted on the carrier for measuring an electrical property of the oils or fats,

an attachment formed as a tubular component,

a carrier part disposed inside said attachment,

measurement electronics connected to the sensor via one or more electrical leads, wherein at least one of the electrical leads is disposed on the carrier part.

2. The device of claim 1, wherein the carrier is formed as one piece with the carrier part.

3. The device of claim 1, wherein at least part of the measurement electronics is disposed on the carrier part.

4. The device of claim 1, wherein the sensor comprises a capacitor.

5. The device of claim 1, wherein the capacitor comprises an interdigital capacitor (IDC).

6. The device of claim 1, wherein the carrier part is made of a non-metallic material.

7. The device of claim 1, wherein the carrier part is made of a non-conducting material.

8. The device of claim 1, wherein the carrier part is made of ceramics.

9. The device of claim 1, wherein the one or more electrical leads are printed on the carrier part.

10. A device for measuring the state of degradation of oil or fat at a temperature comprising:

a carrier;

a sensor for measuring an electrical property of the oil or fat;

a housing comprising electronics for evaluating or displaying a result of measuring the electrical property;

an attachment attaching the sensor to the housing; and

fastening means for fastening the carrier to the attachment, wherein the fastening means thermally separates the sensor disposed on the carrier and the attachment such that adaptation of the carrier and the sensor to the temperature of the oils or fats to be measured is not significantly affected by the attachment.

11. The device of claim 10, wherein the fastening means comprises a seal against the entry of fat or oil into the attachment.

12. The device of claim 10, wherein the fastening means is an adhesive.

13. The device of claim 12, wherein the adhesive forms a mechanical connection between the carrier and the attachment, said mechanical connection being elastic.

14. The device of claim 12, wherein the adhesive has a thermal conductivity of less than 1 W/mK.

15. The device of claim 14, wherein the adhesive has a thermal conductivity of less than 0.1 W/mK.

16. The device of claim 12, wherein the adhesive is a silicone adhesive.

17. The device of claim 10, wherein the sensor is connected to the attachment via the carrier, and wherein the carrier has a thermal conductivity of less than 10 W/mK.

18. The device of claim 17, wherein the carrier has a thermal conductivity of less than 5 W/mK.

19. The device of claim 10, wherein the carrier is a ceramic component.

20. The device of claim 10, comprising a shield surrounding the sensor, wherein the sensor comprises capacitive properties and the shield protects the sensor against effects on the capacitive properties of the sensor that are due to the environment at the point of measurement.

21. The device of claim 20, wherein the shield and the sensors are disposed in a common plane.

22. The device of claim 20, wherein the shield comprises a metallic material.

23. The device of claim 20, wherein the shield is formed by a continuation of the attachment.

24. The device of claim 10, wherein a temperature probe is disposed on the carrier.

25. A process of measuring oil or fat comprising:

bringing a sensor at a temperature into contact with the oil or fat when the oil or fat is in a liquid state and at a higher temperature than the temperature of the sensor;

measuring the dielectric constant of the oil or fat before the temperature of the sensor reaches the higher temperature of the oil or fat;

measuring the temperature of the sensor while the sensor is adapting to the higher temperature of the oil or fat;

determining the higher temperature of the oil or fat from the measured temperatures of the sensor before the temperature of the sensor reaches the higher temperature of the oil or fat; and

using reference values in memory of a measurement device comprising the sensor to determine the dielectric constant of the oil or fat before the temperature of the sensor reaches the higher temperature of the oil or fat.

26. A device for measuring the state of oil or fat comprising:

a housing that can be held by a user;

measurement electronics in the housing;

a sensor for measuring an electrical property of the oil or fat, the sensor being connected to the measurement electronics;

a temperature sensor positioned near the sensor for measuring the temperature of the sensor; and

memory in the housing connected to the measurement electronics and having stored therein reference values associated with the electrical property of the oil or fat, wherein the reference values aid determining the state of the oil or fat based on measurements of the electrical property of the oil or fat and measurements of the temperature of the sensor.