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

• US 20030155935A1
• Filed: 12/27/2002
• Published: 08/21/2003
• Est. Priority Date: 12/28/2001
• Status: Active Grant

• Current Assignee: Xylem Analytics Germany GmbH (Xylem, Inc.)
• Original Assignee: EBRO Electronic GmbH & Co. KG (Xylem, Inc.)
• Inventors: Klun, Wolfgang
• Granted Patent: US 6,822,461 B2
• Time in Patent Office: Days
• US Class Current: 324/664
• 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 or fat comprising a sensor for measuring an electrical property of the oils or fats, wherein the sensor is mounted on a carrier and is connected to measurement electronics via one or more electrical leads, and further comprising a housing for evaluating or displaying the result of the measurement, wherein at least one of the electrical leads is disposed on a 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 the carrier part includes at least part of the measurement electronics.

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

5. The device of claim 4, wherein the capacitor comprises an interdigital capacitor (IDC).

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

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

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

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

20. The device of claim 1, wherein the sensor is surrounded by a shield which protects the sensor against effects on its capacitive properties that are due to the environment at the point of measurement.

21. The device of claim 20, wherein the shielding is disposed in the same plane as the sensor partially surrounds the sensor.

22. The device of claim 20, wherein the shielding consists of a metallic material.

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

24. The device of claim 1, wherein a temperature probe is disposed on the carrier.

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

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

a housing with electronics for evaluating or displaying a result of measuring said electrical property, and,

an attachment for fastening the sensor to the measuring device,

wherein the sensor is disposed on a carrier and is fastened to the attachment with a fastening means, wherein the fastening means thermally separates the sensor and the attachment such that the 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 interior of 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 disposed on a carrier, through which it is connected to the attachment, 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.

25. A process for measuring the state of degradation of oil or fat comprising, measuring the dielectric constant of oil or fat with a sensor, wherein the sensor is brought into contact with the oil or fat in a liquid state, wherein the sensor is at a lower temperature than the oil or fat, and the dielectric constant of the oil or fat is measured while the sensor is adapting to the temperature of the oil or fat.

26. The process of claim 25, wherein the measurement is performed before the sensor attains the temperature of the oil or fat to be measured.

27. The process of claim 25, wherein the measurement is performed at a predefined temperature.

28. The process of claim 25, wherein the measurement comprises monitoring of the temperature of the oil or fat.

29. The process of claim 25, wherein the temperature of the oil or fat is determined from the measured curve of the change of the temperature over time of the sensor and/or the oil or fat.

30. The process of claim 25, wherein the measured value of the dielectric constant provides the temperature of the oil or fat.