Electricity: measuring and testing – Impedance – admittance or other quantities representative of... – Lumped type parameters
Reexamination Certificate
2000-04-21
2002-10-22
Le, N. (Department: 2858)
Electricity: measuring and testing
Impedance, admittance or other quantities representative of...
Lumped type parameters
C324S698000
Reexamination Certificate
active
06469521
ABSTRACT:
The present invention is relative to a device for measuring the state of oils or fats in accordance with the generic. part of claim
1
as well as to a method for measuring the state of a measured material and to a device for carrying out the method.
Oils and fats are very important for human consumption and in particular for the preparation of foods. Thus, many foods, e.g., potatoes or foods which have already been breaded are cooked in hot oils or fats by placing them into these hot fats, which makes them accessible for human consumption. (The term “fats” is intended to denote in particular a solid form of oils in this connection.) In order to cook foods the oils and fats are used in a temperature range of approximately 90° Celsius to 180° Celsius and more. These hot temperatures result in particular in a breakdown or change of the fat which increases more and more during the use of the oil.
This change is a degradation and takes place essentially by means of the oxidation of the oil or fat. Many chemical products are produced thereby such as, e.g., free fatty acids or polymers which not only negatively affect the taste of the prepared dishes but in particular contain substances with which can make one sick and make it necessary to replace such oils, that is, in particular frying fats, on a regular and timely basis. This replacement basically takes place according to criteria which have no direct connection with the chemical change, in particular with the harmful chemical change of the fat. The replacement takes place, e.g., after the passage of a certain time or after other irrelevant criteria. Thus, it occurs in practice that the fats are replaced too early or too late. The first instance produces unnecessary expense whereas a replacement that is too late entails the dangers cited above.
U.S. Pat. No. 3,739,265 teaches a test instrument which checks fat with a sensor to see whether it can still be used. Provision is made thereby to check the oil for its electric properties, in particular its dielectric properties. The test device comprises to this end a key-shaped carrier with a sensor arranged on its bottom which sensor is designed as a capacity sensor. To this end a certain amount of oil is placed on the sensor and the capacity measured with this system is processed in an electric circuit which yields a value- which makes a statement about the degree of degradation of the fat. In addition, a comparison is carried out between the fat or oil to be tested and a standard liquid which must also be measured in a measuring process. The change in the capacity of the sensor is a measure for the degree of degradation of the oil.
U.S. Pat. No. 5,824,889 teaches an oil sensor operating on a capacitive basis for measuring the degradation and contamination of oil. This sensor is used for checking the oil of internal combustion engines. The electric properties of the motor oil form a reference point for the degradation of the oil and for its still sufficient quality. The dielectric constant of a certain oil brand changes thereby within quite specific limits which were determined by tests and therefore yields a measurement for the degradation of the oil.
In addition, motor oil can also be degraded in its quality by other factors, e.g., by the presence of contaminants, e.g., by cooling liquids or gasoline. This can also be a measure of how far the wear on the engine has progressed and of what type it is. Since, e.g., cooling liquid has a significantly higher dielectric constant a significantly higher change of the dielectric constant can be an indication of engine wear.
The sensor described in the U.S. patent for measuring the properties of the oil of internal combustion engines comprises a sensor surface mounted in the oil, e.g., in the oil pan of a motor vehicle. Only a narrow slot is provided on the sensor which permits the passage of oil to the sensor.
The disadvantage of the first-named device is that in order to measure the oil the oil must be filled into a receiving device of an oil sensor. To this end the oil must be removed, e.g., from a deep fat flyer and introduced into the measuring receptacle of the sensor. After its electrical properties have been measured the oil is removed again and the measurement carried out with a reference oil for comparison with the first measurement. Since the oil is present thereby in a very small amount it cools off very rapidly which creates the danger in the case of fats that they become hard, which falsifies the measurement or makes it impossible.
In addition, the manipulation is problematic and the oil used for the measurement must subsequently be removed so that on the whole the process is time-consuming and unpleasant. This device is not suitable for use in practice, that is, without great expense. The device is not suitable for being used directly in the kitchen for directly checking the fat used without preparatory work.
The sensor of U.S. Pat. No. 5,824,889 is not only very bulky on account of its intended uses and not suitable for being used at various locations but it also has the disadvantage that the sensor surface has a covering which makes it difficult for the oil to reach the sensor when the sensor is used at other opportunities. In addition, it would be practically impossible to clean the sensor since this would be too expensive. In particular, this eliminates its being used in conjunction with food fats.
The present invention has the problem of suggesting a measuring device and a method of its operation which device avoids the disadvantages of the state of the art and is suitable by virtue of its easy handling and a suitable measuring method not only for being used under laboratory conditions but can be used in a very variable manner on account of its ability to be handled and operated very simply. In particular, the use of the device in accordance with the invention in the area of measurements, e.g., of frying oils or frying fats should be created without these oils or fats having to be first removed from the pan for measuring.
In addition, the invention should create a device which can be used in a flexible manner which can also be used for determining the quality of other oils, e.g., motor oil. Another target of the invention is to create a measuring device with an oil sensor which can be used in a mobile fashion, that is, without the sensor having to be permanently installed for measuring or having to be integrated in the oil container. In addition, a method should be created which yields precise results.
The design of the measuring device in accordance with the invention brings it about that a device is created which is easy to handle, manipulate and can be reliably operated even when dealing with hot liquids. In addition, it has the advantage that it supplies reliable measured results independently of the temperature of the matter to be measured and without preparatory measures being required in order to be able to use the device. The fact that the attachment is designed as a rod-shaped or tubular element brings it about in an advantageous manner that the measuring head and the housing are rigidly connected to one another so that only one hand is required for operating the measuring device. The handling of flexible cables is eliminated. A reliable handling of the measuring device is assured. In addition, the attachment makes it possible for the operator of the measuring device to be assured in an advantageous manner of a safe interval between the matter to be measured and his hand, which guides the measuring device on the housing. The connection between the measuring head and the evaluation electronics takes place in an advantageous manner via the interior of the attachment.
The designing of the measuring device with a compensator brings it about in an advantageous manner that changes of the sensor itself caused by a change in temperature are compensated. This makes it possible to use the measuring device at different temperatures in a simple and economical manner without expensive methods requiring an adjustment of the de
Geul Willem
Klün Wolfgang
Ebro Electronic GmbH & Co. KG
Jenkens & Gilchrist P.C.
Kerveros James
Le N.
LandOfFree
Method for measuring the state of oils or fats does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for measuring the state of oils or fats, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for measuring the state of oils or fats will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2987087