BACKGROUND

Technical Field

[0001] The embodiments herein generally relate to a device for detecting impurities in gold products, and, more particularly, to a device for detecting ferrous impurities in gold products using magnetic field detection.

Description of the Related Art

[0002] In the course of jewel polishing processes of a jewel work piece, iron-containing impurities may enter into the jewel material manufactured and eventually these impurities give rise to one or more defects in a microstructure of the jewel work piece and affect thereby the characteristics of the jewel work piece. They are referred to as defects and because of their ferrous content, as ferromagnetic defects. The mass of the ferromagnetic impurities in the jewel work piece may be detected using a quality checking process before the jewel work piece is further processed or bought into use.

[0003] Existing solutions or the quality checking process for the detection of ferrous materials in gold jewellery require diligent human labor to use heavy magnets against the gold jewellery to check the attraction of gold jewellery towards the magnet due to presence of any ferrous impurities. Further, this method is effective for detecting huge impurities in centi-meter scale. In general, during jewel polishing processes around 5mm Length x 0.5mm Diameter of ferrous impurities will enter into the jewel material which cannot be detected using magnets because of its very less weight compared to the gold jewellery which has it. Basically, there are few processes available till date, for example X-ray Fluorescence analysis (XRF), ultrasonic measurements etc. for the detection of ferromagnetic impurities in the gold products. By means of XRF Analyzer, impurities can be detected based upon their different compositions of the gold products and the X-ray contrasts associated therewith. XRF analyzer is the most widely used technique in gold industry to detect the elemental composition of the gold jewellery. However, XRF analyzer able to analyze the surface of the gold jewellery which is of 60 micron Depth. After Jewellery manufacturing, impurities present in finished gold Jewellery like Haram, Hollow Chains will be in 2 to 5 cm depth which cannot be detected by the XRF. Hence, XRF analyzer is not suitable for in depth analysis of impurities in the gold jewellery. The ultrasonic measurement method detects ferromagnetic impurities on the gold products based upon the different densities of gold and ferromagnetic impurities. This method involves scattering of ultrasound crystallites of the alloy. The method is therefore suitable only for larger impurities in the gold work piece which are not very thick.

[0004] The widely-used method for gold purity testing is inductively coupled plasma mass spectrometry, (ICP-MS), developed in the l980s. ICP-MS method with high sensitivity than inductively coupled plasma atomic emission spectrometry (ICP-AES). ICP-MS method can analyze almost all elements on Earth, and has a high sensitivity, low detection limit, wide linear range, simple lines and can perform multi-element analysis and so on. But, usage of organic reagents for testing the material after extraction and each sample analysis consumes relatively large time period makes it difficult to use.

[0005] Accordingly, there remains need for device that is capable of detecting the ferromagnetic impurities in a gold products/jewel work piece more precisely without any human labor as well as less time consuming.

SUMMARY

[0006] The main objective of the present invention is to provide a device to detect ferrous impurities in gold products.

[0007] In one embodiment, the present invention relates to an automated device for detecting ferrous impurities in gold products, comprising: (i) a conveyor belt that is configured to receive a gold product to be tested when the automated device is in operation, (ii) a magnetic sensor housing characterized in that comprises, (a) at least one first sensor array that is positioned at an inner top surface of the magnetic sensor housing, wherein the at least one first sensor array comprises a plurality of first sensors; and (b) at least one second sensor array that is positioned below of the conveyor belt, wherein the at least one second sensor array comprises a plurality of second sensors, wherein the at least one first sensor array and the at least one second sensor array are placed in a direction parallel to a relative motion of the conveyor belt, wherein the plurality of first sensors and the plurality of second sensors are configured to sense change in magnetic flux values due to a presence of ferrous impurities in the gold product when the gold product is scanned and generate a signal based on the change in magnetic flux values; and (iii) a control unit comprises, (a) at least one multiplexer configured to receive sensed signal from at least one of the plurality of first sensors or the plurality of second sensors and communicate the sensed signal (b) at least one auxiliary controller configured to receive sensed signal from the at least one multiplexer, process the sensed signal to extract the sensed magnetic flux values associated with the scanned gold product, determine a presence of ferrous impurities in the gold product by comparing the sensed magnetic flux values with a threshold value, and generate a first control signal when the presence of ferrous impurities is determined in the gold product and communicate the first control signal; and (c) a controller that is configured to receive the first control signal from the at least one auxiliary controller, wherein the controller process the first control signal and activates an user indicator to indicate the presence of the ferrous impurities in the gold product.

[0008] In another embodiment, the automated device includes a pair of collection bins that is communicatively coupled with the control unit, wherein the pair of collection bins comprises a first collection bin and a second collection bin, wherein the control unit generates a second control signal to activate the first collection bins to collect the gold product that contains ferrous impurities.

[0009] In yet another embodiment, the sensors of the automated device include at least one of Induction Coil Sensors, Magneto resistive sensors, Hall Effect sensors, Magnetic compass sensors or Flux Gate Sensors.

[0010] In another embodiment, the automated device includes a proximity sensor that is configured to ensure an orientation of the pair of collection bins.

[0011] In further embodiment, at least one auxiliary controller present in the automated device initiates a calibration process of the automatic device by measuring magnetic flux values using at least one of the plurality of first sensors or the plurality of second sensors before placing the gold product inside the magnetic sensor housing and defining the threshold value based on the calibration process.

[0012] In another aspect, the present invention relates to a method of detecting ferrous impurities in the gold products using an automated detection device comprising, (i) calibrating the automated detection device by calculating magnetic flux value before placing gold product in a magnetic sensor housing using a control unit, (ii) placing the gold product to be tested on a conveyor belt, wherein the conveyor belt is in relative motion configured to introduce the gold product to the magnetic sensor housing, wherein the magnetic sensor housing includes at least one first sensor array and at least one second sensor array with plurality of first and second sensors positioned in a direction parallel to a relative motion of the conveyor belt, (iii) detecting change in the magnetic flux value due to a presence of ferrous impurities in the gold product when the gold product is scanned using the plurality of first sensors and the plurality of second sensors and generating a signal based on the change in magnetic flux values, (iv) communicating the sensed signal to the control unit, wherein the control unit includes a controller, at least one multiplexer for receiving sensed signal from at least one of the plurality of first sensors or the plurality of second sensors and communicate the sensed signal, and at least one auxiliary controller for receiving and processing sensed signal from at least one multiplexer to extract the sensed magnetic flux values, determining a presence of ferrous impurities in the gold product by comparing the sensed magnetic flux values with a threshold value, generating a first control signal when the presence of ferrous impurities is determined in the gold product and communicating the first control signal to the control unit, (v) receiving and processing first control signal from the at least one auxiliary controller and activating an user indicator to indicate the presence of the ferrous impurities in the gold product; and (vi) activating the first collection bin from the pair of collection bins based on second control signal generated by the control unit to collect the gold product that contains ferrous impurities.

[0013] In one embodiment, the automated device scans the entire finished gold product up to 7 cm depth and finds any ferrous impurities present in it, according to an embodiment herein.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The embodiments herein will be better understood from the following detailed description with reference to the drawings, in which:

[0015] FIG. 1 is a perspective view of an automated detection device to detect any ferrous impurities present in a gold product, according to an embodiment herein;

[0016] FIG. 2A is a top view of a magnetic sensor housing of the automated detection device of FIG. 1, according to an embodiment herein;

[0017] FIG. 2B a front view of two or more user indicators of the automated detection device of FIG. 1 , according to an embodiment herein;

[0018] FIG. 3 is a user interactive view of a control unit of the automated detection device of FIG. 1 according to an embodiment herein;

[0019] FIG. 4 is a user interactive view of a first auxiliary controller of the automated detection device of FIG. 1 according to an embodiment herein;

[0020] FIG. 5 is a user interactive view of a calibration process performed by the first auxiliary controller of the automated detection device of FIG. 1 according to an embodiment herein;

[0021] FIGS. 6A & 6B are a user interactive view of a decision making process followed by a recalibration process performed by the first auxiliary controller of the automated detection device of FIG. 1 according to an embodiment herein;

[0022] FIG. 7 is a user interactive view of a main controller of the automated detection device of FIG. 1 according to an embodiment herein; and

[0023] FIGS. 8A & 8B are flow diagrams that illustrate a method for detecting any ferrous impurities in the gold product using the automated detection device of FIG. 1 according to an embodiment herein.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0024] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.

[0025] As mentioned, there remains need for a device that is capable of detecting the ferromagnetic impurities in a gold jewel work piece more precisely without any human labor as well as less time consuming. The present embodiment provides an automated device that detects the impurities present in a gold product to be tested. More particularly, the impurity detection device detects any ferrous impurities present in the gold product to be tested, by detecting changes in magnetic field created by any ferrous impurities when the gold product is subjected to an array of magnetic sensor housing through a conveyor belt. The impurity detection device detects ferrous impurities present in the gold product even in nano scale and also detecting even a minute change in the magnetic field more accurately using an array of sensors arranged inside the magnetic sensor housing. Referring now to the drawings, and more particularly to FIGS. 1 through 8B, where similar reference characters denote corresponding features consistently throughout the figures, there are shown preferred embodiments.

[0026] FIG. 1 is a perspective view of the automated detection device to detect any ferrous impurities present in the gold product 102, according to an embodiment herein. The automated detection device includes the gold product 102, the conveyor belt 104, the magnetic sensor housing 106, a control unit 108, two or more user indicators 110A-N, a pair of collection bins 112A & 112B and a supporting structure 114. The gold product 102 to be tested for presence of any ferrous impurities is feed into the conveyor belt 104. The conveyor belt 104 that is in relative motion introduces the gold product 102 into the magnetic sensor housing 106. In one embodiment, the conveyor belt moves in a constant speed of 150 mm per second. The magnetic sensor housing 106 with one or more sensor arrays that detects change in the magnetic field created by any ferrous impurities present in the gold product 102 and communicate to the control unit 108. The control unit 108 processes the signals received from the magnetic sensor housing 106. The control unit 108 generates a control signal to activate the two or more user indicators 110 A-N to indicate the presence of the ferrous impurities in the gold product 102. The control unit 108 provides the control signal to the pair of collection bins 112A & 112B to collect the gold product 102 from the magnetic sensor housing 106 using the conveyor belt 104. The pair of collection bins 112A & 112B collects the gold product 102 with ferrous impurities and the gold product 102 without ferrous impurities respectively in each bin. In one embodiment, control unit 108 provides the input signal to switch between the pair of collection bins to separately collect the gold product 102 that contains ferrous impurities in the collection bin 112A from the gold product 102 that doesn’t contain ferrous impurities in the collection bin 112B. In one embodiment, the pair of collection bins 112A & 112B contains a motor means for switching between the pair of collection bins 112A & 112B. In another embodiment, the pair of collection bins 112A & 112B contains a proximity sensor means to ensure the orientation of the pair of collection bins 112A & 112B. The supporting structure 114 provides support to the impurity detection device to perform the testing process. In one embodiment, the height of the gold product 102 to be tested is of less than 15 mm so that the gold product 102 is not destructed inside the impurity detection device.

[0027] FIGS. 2 A is a top view of the magnetic sensor housing 106 of the impurity detection device of FIG. 1, according to an embodiment herein. In FIG. 2A, the magnetic sensor housing 106 contains a first sensor array 202 located at the at an inner top surface of the magnetic sensor housing 106 and a second sensor array 204 located below of the conveyor belt 104. Both the first sensor array 202 and the second sensor array 204 are placed in a direction parallel to the relative motion of the conveyor belt 104. Each sensor array contains a number of sensors that are positioned in an optimal distance among themselves and are arranged in a specific orientation with the conveyor belt 104 to accurately detect the change in the magnetic field inside the magnetic sensor housing 106. In one embodiment, the magnetic sensor housing includes plurality of sensor arrays with each sensor array contains a number of sensors that are positioned in an optimal distance among themselves and are arranged in a specific orientation to improve the accuracy of detection.

[0028] In one embodiment, the sensors are at least one of but not limited to, Induction Coil Sensors, Magneto resistive sensors, Hall Effect sensors, Magnetic compass sensors, Flux Gate Sensors. In one embodiment, the sensors detect the magnetic field using multi-axis detection method for higher accuracy of detection of ferrous impurities. In one embodiment, one or more sensor arrays can be placed inside the magnetic housing 106 to accurately detect the ferrous impurities in the gold product 102. In one embodiment, one or more sensor arrays can be placed inside the magnetic housing 106 in multiple directions and in multiple distances to accurately detect the ferrous impurities in the gold product 102. In one embodiment, the first sensor array 202 is located at the inner top surface of the magnetic sensor housing 106 at a specific distance from the conveyor belt 104 and the specific distance is both (a) a minimum distance from the conveyor belt 104 for not missing the detection of nano scale of ferrous impurities in the gold product 102 and (b) a maximum distance the conveyor belt 104 for the gold product 102 to pass through the magnetic sensor housing 106 without any damage and hindrance.

[0029] FIG. 2B a front view of two or more user indicators 110A-N of the automated detection device of FIG. 1, according to an embodiment herein. In one embodiment, the user indicator 110A is a power switch. The power switch 110A is to actuate the impurity detection device using electricity. In one embodiment, the user indicator 110B is a mode selection switch with a LED indicator displaying a green color. The mode selection switch 110B enables the collection of the gold product from the pair of collection bins 112A & 112B. In one embodiment, on pressing the mode selection switch 110B once, the gold products with ferrous impurities are collected from the collection bin 112A. In another embodiment, on pressing the mode selection switch 110B twice, the gold products without any ferrous impurities are collected from the collection bin 112B. In yet another embodiment, on pressing the mode selection switch 110B thrice, the impurity detection device is actuated back to a normal position and ready for next cycle of testing. In one embodiment, the user indicator 110C is a calibration switch with a LED indicator displaying a yellow color. In one embodiment, the calibration switch 110B is pressed to trigger manually the calibration process of the impurity detection device and starts a new testing process. In another embodiment, the calibration switch 110B aligns the pair of collection bins 112A & 112B in position. In one embodiment, the user indicator 110D is a status indicator with a LED displaying the green color. In one embodiment, the status indicator 110D displays the green color continuously when the impurity detection device is performing the testing process. In another embodiment, the status indicator 110D displays the green color intermittently when the impurity detection device is performing the calibration process. In another embodiment, the status indicator 110D do not display the green color when the impurity detection device in power off state. In one embodiment, the user indicator 110E is a detection indicator with a LED displaying a red color to indicate that the impurity detection device detects any ferrous impurity in the gold product 102. In another embodiment, the user indicator 110E includes a buzzer means that indicates when the impurity detection device detects any ferrous impurity in the gold product 102 by a buzzer sound. In one embodiment, the user indicator 110F is a waiting status indicator with a LED displaying the yellow color. In one embodiment, the waiting status indicator 110F displays the yellow color continuously when the impurity detection device is in idle state and not performing the testing process. In another embodiment, the waiting status indicator 110F displays the yellow color continuously when the impurity detection device is in idle state and the pair of collection bins 112A & 112B is safe to handle manually. In yet another embodiment, the waiting status indicator 11 OF displays the yellow color intermittently when the impurity detection device switches from the idle state to the testing process. In one embodiment, there is a plurality of user indicators 110A-N based on the output provided by the control unit 108.

[0030] FIG. 3 is a user interactive view of the control unit 108 of the automated detection device of FIG. 1 according to an embodiment herein. The control unit 108 includes a first multiplexer 302, a first auxiliary controller 304, a second multiplexer 306, a second auxiliary controller 308 and a main controller 310. The first multiplexer 302 collects the signals from the one or more sensors of first sensor array 202 and communicates the received signal to the first auxiliary controller 304. In one embodiment, the signals include magnetic flux values sensed by the one or more sensors of first sensor array 202 and the second sensor array 204. The first auxiliary controller 304 receives the signals and performs a first decision including the presence of any ferrous impurities in the gold product 102 based on the signals received from first sensor array 202. The first auxiliary controller 304 communicates the first decision to the main controller 310. Similarly, the second multiplexer 306 receives the signals and performs a second decision including the presence of any ferrous impurities in the gold product 102 based on the signals received from second sensor array 204. The second auxiliary controller 304 communicates the second decision to the main controller 310. The main controller 310 based on the first decision and the second decision generates a final output. The final output includes (i) a signal to the two or more user indicators 110A-N to indicate the whether there is any impurity present in the gold product and (ii) a signal to the pair of collection bins 112A& 112B to collect the gold product 102 leaving the magnetic sensor housing 106. In one embodiment, the final output includes the signal to the user indicator 110E to display the red color LED to indicate that the impurity detection device detected any ferrous impurity in the gold product 102 with the buzzer sound signal using the buzzer means. In another embodiment, the final output includes a signal to the motor means of the pair of collection bins 112A &112B to rotate to switch between the pair of collection bins 112A & 112B for collecting the gold product 102 in the respective bin. In one embodiment, the communication among the first sensor array 202, the second sensor array 204, the first auxiliary controller 304, the second auxiliary controller 304 and the main controller 310 is by at least one of Inter-Integrated Circuit (I2C) bus, Serial Peripheral Interface (SPI) bus, Controller Area Network (CAN) bus, serial bus or Analog-to-Digital Converter (ADC).

[0031] FIG. 4 is a user interactive view of the first auxiliary controller 304 of the impurity detection device of FIG. 1 according to an embodiment herein. At step 402, the first auxiliary controller 304 initializes the first auxiliary controller communication process of the automated detection device. In one embodiment, the initialization of the first auxiliary controller communication process includes (i) initializing one or more data buffers that enable the storage of previous and real-time magnetic flux values that are sensed by the one or more sensors of the first sensor array 202 and the second sensor array 204 and (ii) setting one or more sensor operation tasks of the impurity detection device. In another embodiment, the one or more sensor operation tasks include providing instructions to the first sensor array 202 and the second sensor array 204 to sense the signals for every“t” seconds. In yet another embodiment,“t” seconds varies from 2 seconds to n seconds according to the user operation needs to perform necessary operations. At step 404, the first multiplexer 302 communicates a reference signal including initial magnetic flux values from the first sensor array 202 and the second sensor array 204 to the first auxiliary controller 304 to calibrate and set the magnetic threshold values. In one embodiment, the initial magnetic flux value is sensed by the first sensor array 202 and the second sensor array 204 before the gold product 102 is tested by the impurity detection device. In one embodiment, the magnetic threshold values are stored in the one or more data buffers to determine the presence of any ferrous impurities in the gold product 102 by the main controller 310. At step 406, a status signal for updating the status of the impurity detection device in the one or more user indicators 110A-N is communicated by the first auxiliary controller 304 to the main controller 310. At step 408, the first auxiliary controller 304 determines the presence of any ferrous impurities in the gold product 102 based on a detection signal communicated by the first multiplexer 302 and communicates the first decision to the main controller 310. In one embodiment, the first decision includes (i) any ferrous impurities are present in the gold product 102 or (ii) no ferrous impurities are present in the gold product 102. In one embodiment, the detection signal includes detection magnetic values from the first sensor array 202 when the gold product 102 is tested by the impurity detection device. In another embodiment, the detection signal includes detection magnetic values from the second sensor array 204 when the gold product 102 is tested by the automated detection device. At step 410, the first auxiliary controller 304 checks whether the automated detection device to perform a recalibration process or not. In one embodiment, when the automated detection device performs the recalibration process, the first auxiliary controller 304 (i) performs the step 404 to recalibrate the magnetic threshold values and (ii) performs the step 406 by communicating the status of recalibration to the main controller 310. At step 410, in one embodiment, a control signal is communicated from the main controller 310 to the first auxiliary controller 304 to perform the recalibration process initiated by other externally sources.

[0032] In one embodiment, the second auxiliary controller 308 performs all the steps from 402 - 410 and provides the second decision to the main controller 310. In one embodiment, the second decision includes at least one of (i) any ferrous impurities are present in the gold product 102 or (ii) no ferrous impurities are present in the gold product 102. In another embodiment, the nth auxiliary controller performs all the steps from 402 - 410 and provides the nth decision to the main controller 310. In another embodiment, the nth decision includes at least one of (i) any ferrous impurities are present in the gold product 102 or (ii) no ferrous impurities are present in the gold product 102.

[0033] FIG. 5 is a user interactive view of the calibration process by the first auxiliary controller 304 of the impurity detection device of FIG. 1 according to an embodiment herein. In step 502, the calibration process of the impurity detection device is initiated using first auxiliary controller 304 and second auxiliary controller 308. In one embodiment, the calibration process is initiated by at least one of (i) automatically triggered or (ii) user triggered. In step 504, the status signal for updating a calibration status of the impurity detection device in the one or more user indicators 110A-N is communicated to the main controller 310. At step 506, the magnetic flux values are obtained from the one or more sensors of the first sensor array 202 and the second sensor array 204. In step 508, the magnetic flux values are stored in one or more data buffers. In step 510, a median value of the stored magnetic values is determined and set as an impurity detection set point. In one embodiment, the median value of the stored magnetic values that are obtained for all the 3-axes of the first sensor array 202 and the second sensor array 204 is determined and set as an impurity detection set point. In step 512, the impurity detection set point is stored in one or more data buffers for reference.

[0034] FIGS. 6A & 6B is a user interactive view of a decision making process followed by a recalibration process performed by the first auxiliary controller 304 of the automated detection device of FIG. 1 according to an embodiment herein. In step 602, the magnetic flux values are obtained from the one or more sensors of the first sensor array 202 to obtain the real time data. In one embodiment, the magnetic flux values are obtained from the one or more sensors of the first sensor array 202 using at least one of I2C communication, SPI communication or CAN communication. In step 604, determining whether the real time data is within an expected range. In one embodiment, the expected range is the range of magnetic flux values that is obtained in previous process. In step 606, when the real time data is within the expected range then the real time data is filtered using a median noise filter for filtering unwanted noise signals attached with the real time data. When the real time data is not within the expected range then the real time data is obtained as in the step 602. In step 608, the filtered real time data obtained in step 606 is compared with the impurity detection set point of step 510. In one embodiment, the differential threshold is obtained manually based on trial and error experiments with a plurality of gold products 102. In step 610, when the difference between the filtered real time data and the impurity detection set point is greater than an impurity detection threshold then the first decision of the presence of any ferrous impurities in the gold product 102 is communicated to the main controller. In step 612, when the difference between the filtered real time data and the impurity detection set point is not greater than an impurity detection threshold the filtered real time data obtained in step 606 is added to the one or more data buffers as noise values. FIG. 6B is a user interactive view of a recalibration process performed by the first auxiliary controller of the impurity detection device of FIG. 1 according to an embodiment herein. In step 614, when the noise values are added to the one or more data buffers the recalibration process is initialized. In one embodiment, the recalibration process is initiated when“n” noise values are added. In another embodiment,“n” can be from 1 to 100. In step 616, a new mean value is calculated for noise values added in the one or more data buffers. In step 618, the new mean value is compared with a calibration set point. In step 620, when the difference between the new mean value and the calibration set point is not greater than calibration threshold then the step 614 is repeated. In step 622, when the difference between the new mean value and the calibration set point is greater than the calibration threshold, a new calibration set point is updated. In step 624, the status signal for updating the calibration status of the impurity detection device is communicated to the main controller 310 for updating to a ready status of the impurity detection device.

[0035] In one embodiment, the second auxiliary controller 308 of the automated detection device of FIG. 1 performs all the steps 602-622 and communicates the second decision to the main controller 310. In one embodiment, the FIG. 6B including the steps 614-624 is performed when the recalibration process is triggered manually. In another embodiment, when the recalibration process is triggered manually, the new mean value is obtained from the real time magnetic values stored in the one or more data buffers. [0036] FIG. 7 is a user interactive view of the main controller 310 of the impurity detection device of FIG. 1 according to an embodiment herein. At step 702, the main controller 310 will be initialization mode. In initialization mode, all the hardware ports of the impurity detection device are supplied with electric current to perform the testing process. At step 704, the main controller 310 triggers the realignment of the pair of collection bins 112A&112B based on a position signal from the proximity sensor means of the pair of collection bins 112A&112B. At step 706, the main controller 310 calibrates the impurity detection device based on the magnetic threshold values and set new magnetic threshold values. At step 708, the main controller 310 enables the impurity detection device to perform the testing process of the gold product 102. Further, the main controller 310 provides indicator signals to the two or more user indicators 110A-N to indicate the calibration state, at step 706. At the step 708, the main controller 310 collects the detection signals and the first decision and the second decision from the first auxiliary controller 304 and the second auxiliary controller 308 respectively. Further, the main controller 310 provides indicator signals to the two or more user indicators 110A-N to indicate the normal state, at step 708. At step 710, the main controller 310 actuates the impurity detection device in a detection mode and process from the first decision and the second decision of both the first auxiliary controller 304 and the second auxiliary controller 306. Further, the main controller 310 provides a collection signal to the pair of collection bins 112A-B to collect the gold product 102 after tested. At step 712, the main controller 310 receives the position signal from the proximity sensor means to check whether the gold product 102 is collected or not. Further, the main controller 310 switches the post detection of the impurity checking device to the normal mode of step 708, when the main controller 310 receives the position signal from the proximity sensor means. At step 714, the main controller 310 activates a standby mode of the impurity checking device when the gold product 102 to be tested is yet to feed in the conveyor belt 104. The main controller 310 also switches between the steps 708 and 714 when the gold product 102 is tested, determined, collected and when ready to a next product to be tested.

[0037] FIG. 8 is a flow diagram that illustrates a method for detecting any ferrous impurities in the gold product 102 using the automated detection device of FIG. 1 according to an embodiment herein. At step 802, the gold product 102 to be tested is received in the magnetic sensor housing 106 using the conveyor belt 104. At step 804, the first sensor array 202 and the second sensor array 204 senses the change in the magnetic flux values due to the presence of any ferrous impurities in the gold product 102. At step 806, the first multiplexer 302 and the second multiplexer 306 collects and communicates the sensed signals from the first sensor array 202 and the second sensor array 204 respectively to process further. At step 808, the first auxiliary controller 304 and the second auxiliary controller 308 receives the sensed signals from the first multiplexer 302 and the second multiplexer 306 respectively. At step 810, the first auxiliary controller 304 and the second auxiliary controller 308 determines the presence of any ferrous impurities in the gold product 102 by comparing the magnetic flux values with the magnetic threshold values. At step 812, the first auxiliary controller 304 and the second auxiliary controller 308 communicates the first decision and the second decision on the presence of any ferrous impurities in the gold product 102 respectively. At step 814, the main controller 310 receives the first decision and the second decision on the presence of any ferrous impurities in the gold product 102 and processes both the decisions. At step 814, further the main controller 310 processes the first decision and the second decision. At step 816, the main controller 310 communicates the indicator signal to the two or more user indicators 110A-N based on the first decision and the second decision and also communicates the position signal to the pair of collection bins 112A-B. The position signal includes the trigger of the motor means to switch between the pair of collection bins 112A-B to collect the gold product 102 from the conveyor belt 104 in the respective bin.

[0038] In one embodiment, the impurity detection device performs the calibration process to provide the magnetic threshold values for processing by the first auxiliary controller 304 and the second auxiliary controller 308. In another embodiment, the impurity detection device is triggered manually to perform the calibration process to provide the magnetic threshold values for processing by the first auxiliary controller 304 and the second auxiliary controller 308. In one embodiment, plurality of gold products 102 is tested by the impurity detection device in continuous manner. In one embodiment, the magnetic sensor housing 106 includes one or more sensor arrays 202, 204 up to N. In one embodiment for each sensor array 202, one multiplexer 302 and one auxiliary controller 304 is attached to collect, communicate and processes the signals to determine a decision. In one embodiment, the main controller 310 receives decisions from the one or more auxiliary controllers 304-N to provide the indicator signal and the position signal.

[0039] The present invention is an automated process and eliminates human intervention and verification. The present invention is a unique method of identification of ferrous impurities in the gold product 102 using the magnetization principles. The impurity detection device and method is more accurate as well as less time consuming and convenient to use for any number of times. As each and every sensor signal sensed in 3 axes are considered for detecting impurity, this impurity detection device is more accurate in determining the presence of ferrous impurities in the gold product 102 in nano scale. [0040] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments.