DEVICE FOR DETECTING FUEL LEVEL USING ELECTRICAL CAPACITY

Abstract

Device for detecting a fuel level using an electrical capacitance mounted on a printed circuit board (PCB), comprising: a level sensor unit (1) having multiple level sensors (1a-1d), wherein pairs of level sensors, comprising the multiple level sensors spaced apart by a predetermined distance, are each located at a predetermined position in a vertical direction on one side of the PCB to measure a fuel level; an information processor (2) which uses fuel level information transmitted by the level sensor unit (1) to calculate the electrical capacitance of the fuel and to calculate a final fuel level based on the calculated electrical capacitance; and a temperature sensor unit (3) with a thermistor located on a lower section of the level sensor unit (1).to measure the temperature of the fuel, wherein the information processor (2) is designed to calculate the final level of the fuel by calculating the electrical capacity of the fuel depending on a predetermined height at which the corresponding pair of level sensors is located, only if the fuel simultaneously comes into contact with the multiple level sensors contained in the pair of level sensors and the information about the level of the fuel is simultaneously transmitted by all level sensors forming the pair of level sensors, and controls an operating state of an externally provided heating device to melt the fuel when the temperature data measured by the temperature sensor unit (3) corresponds to a predetermined temperature.

Description

Technical FieldThe present disclosure relates to a device for detecting a fuel level using an electric capacity, and more particularly to a device for detecting a fuel level using an electric capacity, which is disposed in a tank or a flange in which fuel can be accommodated to measure the electric capacity depending on a contact area with the fuel, thereby calculating a level (a height) of the fuel therein.BackgroundA representative example of technologies for measuring a level of fuel may include capacity execution.The capacity execution detects a change in capacity due to contact with fuel. A level sensor of the capacity design is expediently used here to detect a level of a water tank in a water purification device or of an engine oil or of a fuel quantity of a vehicle.However, since the capacity type level sensor is disposed in a tank or a flange in which the fuel is stored, there is a problem that, in the case of a fuel tank, when a vehicle runs up or down a road or a left or right turn, the fuel tank and the fuel stored therein incline, and a fuel amount smaller or larger than the actual fuel amount can be detected.Moreover, a reference capacitor used for the capacitance type level sensor is ideally designed so that the capacitance has a constant value. However, a parasitic capacitance is generated depending on the external environment (temperature, humidity, dielectric constant of a sensor shape, etc.) in which the level sensor is installed. In this way, the capacitance of the reference capacitor changes due to the parasitic capacitance.The change in the capacitance of the reference capacitor may result in malfunction of the level sensor, and therefore a remaining amount of internal fuel may not be properly checked.Korean Patent Laid-Open Publication No. KR 10 1996 0 037 340 A ("Apparatus for Detecting Fuel for Fuel Tank") discloses an apparatus for detecting a capacity-type fuel for a fuel tank, which is capable of more accurately detecting the remaining amount of the fuel in the fuel tank by avoiding fuel amount detection errors that may occur due to moisture content in the fuel tank, change in temperature, inflow of impurities, and inclination.Korean Patent Laid-Open Publication No. KR 10 2000 024 078 A ("Algorithm for Detecting an Initial Position and Starting a BLDC motor using an inductance change") discloses that a BLDC motor is operated with a predetermined pulse train obtained by a change in inductance without a separate sensor to detect a rotational position in a stopped state, and an initial driving algorithm can smoothly execute initial driving.US 5 406 843 A relates to a digital liquid level measuring device for detecting fluctuations in the dielectric of a substance to be measured. The device comprises a capacitive element arrangement with a plurality of individual (i.e. segmented) input plates which are arranged along a measurement axis of a liquid to be detected. The assembly also includes a common output plate having a length sufficient to span the entire length of the input plates. A control unit applies successive DC excitation pulses to the input plates, thereby coupling a series of output currents to the output plate. The output currents are fed to a current-voltage amplifier which generates a series of corresponding analog output voltages. The analog output voltages are then input to a peak voltage detector circuit to generate a series of peak voltage signals representing the magnitudes of the analog output voltages. The controller converts each of the peak voltage signals into a corresponding digital value and stores each of the digital values in an integrated memory. The control unit then successively compares each of the values with at least one predetermined reference value indicative of an output produced by an input plate disposed in air until a predetermined difference is detected between the reference value and one of the stored digital values. This indicates a predetermined difference in the dielectric and thus indicates that a corresponding input plate is at least partially immersed in liquid.JP H09-79 887 A relates to an electrostatic capacity level meter having a sensor section disposed with a plurality of pairs of level sensors each consisting of a pair of opposing electrodes in the height direction in a tank in which a liquid is stored, a sensor selection section that selects the level sensors one by one, an electrostatic capacity measurement section, and a control calculation section having a program memory that performs measurement of the electrostatic capacity signal and calculation of the level at individual level sensors therein. The electrostatic capacity type sensors include an air sensor fully exposed to the air to measure the air electrostatic capacity, a liquid level sensor having the liquid level, and a submergence sensor fully immersed in the liquid to measure the submergence electrostatic capacity. The electrostatic capacity of the liquid level sensor and the height of the liquid level are measured based on the air electrostatic capacity of the air sensor and the immersion electrostatic capacity of the immersion sensor.SummaryThe present invention provides an apparatus for detecting a fuel level using an electric capacity as defined in claim 1.The dependent claims define preferred and / or advantageous embodiments of the invention.An embodiment of the present invention is directed to providing an apparatus for detecting a fuel level using an electric capacitance disposed in a fuel tank or a flange in which the fuel may be accommodated, to measure the electric capacitance depending on a contact area with the fuel, thereby calculating the level (height) of the accommodated fuel.According to a general aspect, an apparatus for detecting a fuel level using an electric capacitance mounted on a printed circuit board (PCB)) includes: a level sensor unit including a plurality of level sensors, pairs of level sensors including the plurality of level sensors spaced apart from each other by a predetermined distance being provided at a predetermined position in a height direction on a side of the PCB, respectively, to measure a level of the fuel; and an information processor that uses information regarding the fuel level transmitted from the level sensor unit to calculate the electric capacitance regarding the fuel and calculate a final level of the fuel depending on the calculated electric capacitance, and a temperature sensor unit including a thermistor, which is provided at a lower portion of the level sensor unit to measure a temperature of the fuel, wherein the information processor is configured to calculate the final level of the fuel by calculating the electric capacity of the fuel depending on a predetermined height at which the corresponding pair of level sensors is located only when the fuel simultaneously comes into contact with the plurality of level sensors included in the pair of level sensors and the information on the level of the fuel is simultaneously transmitted from all of the level sensors constituting the pair of level sensors, and controls an operation state of an outside heater device to melt the fuel when the temperature data measured by the temperature sensor unit corresponds to a predetermined temperature.The information processor may employ the information on the level of the fuel transmitted from the pair of level sensors transmitted from among the plurality of pairs of level sensors to which the information on the level of the fuel is transmitted at an uppermost portion in the height direction of the PCB to calculate the electric capacity of the fuel and the final level of the fuel depending on the calculated electric capacity when the information on the level of the fuel is simultaneously transmitted from the plurality of pairs of level sensors.The information processor may include: a converter that converts level data of the fuel transmitted from the plurality of level sensors of the level sensor unit into digital data; and a controller (MCU) that uses the digital data converted by the converter and temperature data of the fuel measured by the temperature sensor unit to calculate the final level of the fuel.The fuel level detecting device may further include: a shield provided on the other side of the PCB, and a shield plate for shielding interference of an external magnetic field.According to another general aspect not forming part of the claimed invention, an apparatus for detecting a fuel level using an electric capacitance mounted on a printed circuit board (PCB) includes: a reference sensor unit provided at a lower portion of a side of the PCB to measure a dielectric constant of the fuel; a level sensor unit including a plurality of level sensors provided at an upper portion of the reference sensor unit in a longitudinal direction of a side of the PCB to measure a level of the fuel; and an information processor that uses information on the fuel transmitted from the reference sensor unit and the level sensor unit to calculate the electric capacity with respect to the fuel and to calculate a final level of the fuel depending on the calculated electric capacity, wherein the information processor uses the plurality of level sensors that are spaced apart from each other by a predetermined distance and form pairs, and uses an average value of level data of the fuel transmitted from the plurality of pairs, respectively.The fuel level detection device may further include: a temperature sensor unit including a thermistor provided adjacent to the reference sensor unit in the width direction to measure a temperature of the fuel.The information processor may include: a converter that converts dielectric constant data of the fuel transmitted from the reference sensor unit and level data of the fuel transmitted from the level sensor unit into digital data; and a controller (MCU) that uses the digital data converted by the converter and temperature data of the fuel measured by the temperature sensor unit to calculate the final level of the fuel.The fuel level detection device may further include: a shield provided on the other side of the PCB, and a shield plate for shielding interference of an external magnetic field.The level sensor can be designed as an electrode plate with a width of at least 8 mm.Other features and aspects will become apparent from the following detailed description, drawings and claims.Brief Description of the DrawingsFIG. 1 is a diagram illustrating an example in which a device for detecting a fuel level using an electric capacitance according to an embodiment of the present invention is mounted on a printed circuit board (PCB). FIG. 2 is a block diagram schematically illustrating the apparatus for detecting a fuel level using an electric capacity according to the embodiment of the present invention. FIG. 3 is a diagram illustrating an example in which a device for detecting a fuel level using an electric capacitance according to another embodiment of the present invention is mounted on a printed circuit board (PCB). FIG. 4 is a block diagram schematically illustrating the apparatus for detecting a fuel level using an electric capacity according to the other embodiment of the present invention.Detailed Description of EmbodimentsHereinafter, an apparatus for detecting a fuel level using an electric capacity according to an embodiment of the present invention will be described with reference to the accompanying drawings. The drawings introduced hereinafter are provided by way of example so as to sufficiently explain the concept of the present invention to those skilled in the art to which the present invention pertains. Therefore, the present invention is not limited to the accompanying drawings provided below, but may be embodied in other forms. Moreover, like reference numerals designate like elements throughout the specification.Technical terms and scientific terms used in the present specification have the general meaning understood by those skilled in the art to which the present invention pertains unless otherwise defined. A description for known functions and configurations that would unnecessarily obscure the gist of the present invention will be omitted in the following description and the accompanying drawings.First EmbodimentAn apparatus for detecting a fuel level using an electric capacity according to an embodiment of the present invention is configured to include a plurality of level sensors, the plurality of level sensors spaced apart from each other by a predetermined distance being provided at each predetermined location while being paired to minimize an operation for calculating a remaining amount of fuel at each time the fuel is detected, thereby rapidly measuring the remaining amount of fuel.FIG. 1 is a diagram illustrating an example in which a device for detecting a fuel level using an electric capacitance according to an embodiment of the present invention is mounted on a printed circuit board (PCB). FIG. 2 is a control block diagram of the apparatus for detecting a fuel level using an electric capacity according to the embodiment of the present invention.An apparatus for detecting a fuel level using an electric capacity according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 and 2.As illustrated in FIGS. 1 and 2, the electric-capacity fuel level detection apparatus according to the embodiment of the present invention may be configured to include a level sensor unit 1 having a plurality of level sensors and an information processor 2, wherein the electric-capacity fuel level detection apparatus is preferably mounted on the PCB to easily supply power as described above.Moreover, it is preferable that the apparatus for detecting a fuel level using an electric capacity according to the embodiment of the present invention is disposed in a tank or a flange in which fuel may be accommodated to check the remaining amount of the fuel in the tank or the flange.Each component will be described in detail below.The level sensor unit 1 is configured to include a plurality of level sensors provided at each location in a height direction on one side of the PCB, thereby measuring a level of the fuel. As illustrated in FIG. 1, in the level sensor unit 1, a plurality of level sensors are configured as a pair, the pair of level sensors being provided at a respective predetermined location on one side of the PCB, to transmit information on the fuel, such as the set level of the fuel, at the respective location when contact with the fuel occurs.That is, as shown in FIG. 1, when eight level sensors are constructed in four pairs 1a, 1b, 1c and 1d and then present at the predetermined locations, the information on the level of the fuel is transmitted as "empty" when the fuel comes into contact only with the pair of level sensors 1a disposed at the bottom portion, the information on the level of the fuel is transmitted as "full" when the fuel comes into contact with a pair of level sensors 1d disposed at the top portion, and the information on the level of the fuel is transmitted as "1 / 3 full" when the fuel comes into contact with a pair of level sensors 1b present at the middle portion, and the information on the level of the fuel is transmitted as "1 / 2 full" when the fuel comes into contact with another pair of level sensors 1c, thereby measuring a height of the fuel.In the level sensor unit 1 according to the first embodiment, depending on the information about the predetermined level at the current location where the level sensor unit is located, the operation can be performed with as little effort as possible to transmit the information about the level of the fuel, so that the level of the fuel can be quickly detected.The information processor 2 may use the information on the fuel transmitted from the level sensor unit 1 to calculate the electric capacity of the fuel, thereby calculating a final level (height) of the fuel.Only when the electric capacities of the fuel are calculated the same by the plurality of level sensors constituting a pair of level sensors, that is, when the fuel simultaneously comes into contact with the plurality of level sensors constituting a pair, the information processor may determine and calculate the final level (height) of the fuel.When the information on the level of the fuel is simultaneously transmitted from the plurality of pairs of level sensors, the information processor 2 may employ the information on the level of the fuel transmitted from the pair of sensors disposed at the uppermost portion in the height direction of the PCB among the plurality of pairs of level sensors to which the information on the level of the fuel is transmitted, to calculate the electric capacity of the fuel, thereby calculating the final level (height) of the fuel.For example, it goes without saying that another pair of the level sensors 1a and another pair of the level sensors 1b come into contact with the fuel when the fuel comes into contact with the pair of the level sensors 1c. For this reason, when the information on the level of the fuel is simultaneously transmitted from the plurality of pairs of level sensors, the information processor 2 may employ the information on the level of the fuel transmitted from the pair of level sensors 1 carranged at the uppermost portion in the height direction of the PCB among the plurality of pairs of level sensors to which the information on the level of the fuel is transmitted to, to calculate the electric capacity of the fuel, thereby calculating the final level (height) of the fuel.At this point, it should be noted that the fuel level detection apparatus using an electric capacity according to the embodiment of the present invention may be configured to further include a temperature sensor unit 3 including a thermistor to calculate a dielectric constant and a capacity that increases or decreases depending on the temperature of the fuel.The temperature sensor unit 3 is provided at a lower portion of the level sensor unit 1 to measure the temperature of the fuel.More specifically, as illustrated in FIG. 2, the information processor 2 may be configured to include a converter 2 aand a controller (MCU) 2 b.The converter 2 acan convert level data of the fuel transmitted from the plurality of level sensors of the level sensor unit 1 into digital data.The controller 2 bmay use the digital data converted by the converter 2 aand temperature data of the fuel measured by the temperature sensor unit 3 to correct and calculate the final level (height) of the fuel.At this point, it should be noted that, when the temperature data of the fuel measured by the temperature sensor unit 3 corresponds to a frost temperature of the fuel, the controller 2 bcontrols heating means such as a heater provided outside to melt the fuel.Since urea, etc., may freeze during winter season, a level measurement may lead to undefined results, in particular. Therefore, when it is detected that the fuel reaches the freezing point depending on the temperature data of the fuel measured by the temperature sensor unit 3, the controller 2 bmay drive the heating means such as the heater provided outside to melt the fuel, and then calculate the final level (height) of the fuel.Moreover, the apparatus for detecting a fuel level using an electric capacity according to the embodiment of the present invention may include a shield 50 formed on the other side of the PCB. The shield 50 is formed as a shield plate and is provided on the other side of the PCB to shield interference from an external magnetic field.Second EmbodimentAn apparatus for detecting a fuel level using an electric capacitance according to another embodiment of the present invention determines characteristics of the fuel to set a reference electric capacitance, and includes a plurality of level sensors configured as a plurality of electrode plates to measure a level and a dielectric constant of the fuel with high accuracy, thereby accurately measuring a remaining amount of the fuel.FIG. 3 is a diagram illustrating an example in which a fuel level detection device using an electric capacitance according to the other embodiments of the present invention is mounted on a printed circuit board (PCB), and FIG. 4 is a diagram of control blocks of the fuel level detection device using an electric capacitance according to the other embodiments of the present invention.The apparatus for detecting a fuel level using an electric capacity according to the other embodiments of the present invention will be described in detail with reference to FIGS. 3 and 4.As illustrated in FIGS. 3 and 4, the electric capacity-use fuel level detection apparatus according to the other embodiments of the present invention may be configured to include a reference sensor unit 10, a multi-level sensor unit 20, and an information processor 30, wherein the electric capacity-use fuel level detection apparatus is preferably mounted on the smooth power supply PCB as described above.Moreover, the apparatus for detecting a fuel level using an electric capacity according to the other embodiments of the present invention is preferably disposed in a tank or a flange in which fuel may be accommodated. The remaining quantity of fuel in the tank or in the flange is to be checked.Each component will be described in detail below.The reference sensor unit 10 may be provided at a lower portion on a side of the PCB to measure a dielectric constant of the fuel housed therein.The reference sensor unit 10 may employ the measured dielectric constant of the fuel to detect a type of the fuel. Here, the type of fuel accommodated in a tank or a flange may be gasoline, diesel, ethanol, or water.The reference sensor unit 10 may inherently measure the electric capacitance for each fuel and derive the type of fuel from the measured electric capacitance.The level sensor unit 20 including the plurality of level sensors may be provided on the upper side of the reference sensor unit 10 in a longitudinal direction of a side of the PCB to measure the level of the fuel. As illustrated in FIG. 3, each of the level sensor units 20 may be configured of a plurality of electrode plates, and may measure the height of the fuel by means of a difference in capacitance between the two electrode plates.Specifically, the capacitance corresponding to the magnitude of an electric charge charged by a voltage applied between the respective electrode plates is determined by a dielectric which is insulatively interposed between the respective electrode plates, and therefore the capacitance can be calculated. In this case, surface areas of the electrode plates that communicate with each other (via the fuel) may be a variable in calculation of the capacitance, and therefore it is preferable that an electrode plate constituting the level sensor unit 20 according to the other embodiment of the present invention has a width of at least 8 mm.At this point, it should be noted that the apparatus for detecting a fuel level using an electric capacitance according to the other embodiment of the present invention includes a plurality of level sensors configured of a plurality of electrode plates, thereby improving the measurement accuracy of the level of the fuel.That is, the level data of the fuel measured by a first level sensor and the level data of the fuel measured by a second level sensor are summed, and then an average value is determined by dividing the summed level data of the fuel to measure the electric capacity of the fuel, whereby the level (height) of the fuel is calculated.The information processor 30 may use the information on the fuel transmitted from the reference sensor unit 10 and the level sensor unit 20 to calculate the electric capacity of the fuel, thereby calculating the final level (height) of the fuel.In other words, the information processor 30 may acquire the dielectric constant of the fuel measured by the reference sensor unit 10 and analyze the dielectric constant of the fuel to acquire a kind of the fuel, thereby determining the reference electric capacitance.When the information processor 30 receives the level of the fuel measured by the level sensor unit 20 as described above, the level sensor unit 20 acquires the plurality of level sensors, and thereby the information processor 30 can respectively form an average value of the level data of the fuel transmitted from the plurality of level sensor units 20 and use them.The information processor 30 may use the averaged level data of the fuel transmitted from the level sensor unit 20 depending on the reference electric capacity determined by the reference sensor unit 10 to calculate the current capacity, thereby calculating the level (height) of the fuel.At this point, it should be noted that the apparatus for detecting a fuel level using an electric capacity according to the other embodiments of the present invention is configured to further include a thermistor 40 for calculating the dielectric constant and the capacity that increases or decreases depending on the temperature of the fuel.The temperature sensor unit 40 is provided in a width direction of the reference sensor unit 10 to measure the temperature of the fuel.Specifically, as illustrated in FIG. 2, the information processor 30 may be configured to include a converter 31 and a controller (MCU) 32.The converter 31 receives the dielectric constant data of the fuel transmitted from the reference sensor unit 10 and converts the data into digital data.The level data of the fuel, which is transmitted and averaged by the plurality of level sensor units 20, respectively, may be received and converted into the digital data.The controller 32 may employ the digital data converted by the converter 31 and the temperature data of the fuel measured by the temperature sensor unit 30 to calculate the final level (height) of the fuel.That is, since the dielectric constant data of the fuel transmitted from the reference sensor unit 10 and the averaged level data of the fuel transmitted from the plurality of level sensor units 20 are influenced by the temperature of the fuel, the controller 32 is therefore based on the reference electric capacity determined by the reference sensor unit 10 using the temperature data of the fuel transmitted from the temperature sensor unit 40, to employ the averaged level data of the fuel transmitted from the level sensor unit 20 to calculate the actual capacity and correct the level (height) of the fuel calculated using the calculated capacity, thereby calculating the final level (height) of the fuel.Moreover, the apparatus for detecting a fuel level using an electric capacity according to the other embodiments of the present invention may include a shield 50 formed on the other side of the PCB. The shield is formed of a shield plate and is disposed on the other side of the PCB to shield interference from an external magnetic field.That is, the apparatus for detecting a fuel level using an electric capacity according to the other embodiments of the present invention is based on the reference electric capacity determined by the reference sensor unit 10 to employ the averaged level data of the fuel transmitted from the level sensor unit 20, so as to calculate the initial capacity and correct the initial capacity by considering the temperature data of the fuel transmitted from the temperature sensor unit 40, thereby accurately calculating the final level (height) of the fuel.According to the embodiment of the present invention, the apparatus for detecting a fuel level using an electric capacity having the above-described configuration may be disposed in the fuel tank or the flange in which the fuel may be accommodated to measure the electric capacity depending on the contact area with the fuel, thereby accurately measuring the level (height) of the fuel and outputting the calculated level (height) of the fuel to the user.According to the embodiment of the present invention, the apparatus for detecting a fuel level using an electric capacity may employ the plurality of level sensors to employ the level of the fuel that adjusts due to the level of the fuel in the corresponding level sensors, thereby easily determining the level of the fuel.Moreover, in order to improve the accuracy of fuel level detection, the plurality of pairs of level sensors configured as a pair of electrode plates may be employed to effectively correct the inclination or inclination, and the temperature sensor may be employed to correct the dielectric constant and the capacitance which increases and decreases depending on the temperature, thereby accurately calculating the level of fuel.Moreover, the reference sensor unit may be employed to accurately detect a type of the fuel so as to correctly employ the capacity of the reference capacity, thereby accurately calculating the level of the fuel.Although the present invention has been described in advance by specific embodiments such as detailed components, embodiments and the accompanying drawings, they have been provided only for the purpose of promoting a general understanding of the present invention. Therefore, the present invention is not limited to the embodiments. Various modifications and changes can be made by those skilled in the art to which the present invention pertains from this description.Therefore, the scope of the present invention should not be limited by these embodiments, but the claims and all modifications that are the same as or equivalent to the claims are intended to fall within the scope of the present invention.

Claims

An apparatus for detecting a fuel level using an electric capacitance mounted on a printed circuit board, PCB, comprising: a level sensor unit (1) having a plurality of level sensors (1a-1d), wherein pairs of level sensors including the plurality of level sensors spaced apart from each other by a predetermined distance are each provided at a predetermined location in a height direction on a side of the PCB to measure a level of the fuel; an information processor (2) using information on the fuel level transmitted from the level sensor unit (1) to calculate the electric capacitance of the fuel and calculate a final level of the fuel depending on the calculated electric capacitance; and a temperature sensor unit (3) having a thermistor provided at a lower portion of the level sensor unit (1), A method for measuring a temperature of the fuel, wherein the information processor (2) is configured to calculate the final level of the fuel by calculating the electric capacity of the fuel depending on a predetermined height at which the corresponding pair of level sensors is located only when the fuel simultaneously comes into contact with the plurality of level sensors included in the pair of level sensors and the information on the level of the fuel is simultaneously transmitted from all of the level sensors constituting the pair of level sensors, and control an operation state of an outside heater device to melt the fuel when the temperature data measured by the temperature sensor unit (3) corresponds to a predetermined temperature.The fuel level detection device according to claim 1, wherein the information processor (2) uses the information on the level of the fuel transmitted from a pair of level sensors (1a-1d) disposed at an uppermost portion in the height direction of the PCB among a plurality of pairs of level sensors (1a-1d) to which the information on the level of the fuel is transmitted, to calculate the capacity of the fuel and calculate the final level of the fuel depending on the calculated electric capacity when the information on the level of the fuel is simultaneously transmitted from the plurality of pairs of level sensors (1a-1d).The fuel level detection apparatus according to claim 1, wherein the information processor comprises: a converter (2a) that converts level data of the fuel transmitted from the plurality of level sensors (1a-1d) of the level sensor unit (1) into digital data; and a controller (2b) that uses the digital data converted by the converter (2a) and temperature data of the fuel measured by the temperature sensor unit (3) to calculate the final level of the fuel.The fuel level detection apparatus according to any one of claims 1-3, further comprising: a shield (50) formed on the other side of the PCB and having a shield plate for shielding interference of an external magnetic field.

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