Hello Mohammed Thameemul Ansari
                            
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                                Sven Friedel
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                                                Posted:
                            
                                1 decade ago                            
                            
                                24 mars 2015, 10:24 UTC−4                            
                        
                        
                                                    Hi Mohammed,
for this purpose you should use magnetic fields with time-dependent analysis.
As far as I remember from my studies a fluxgate magnetometer uses the second harmonic 
generation. A magnetically nonlinear material is driven into saturation and the actual
measurement signal, proportional to the exterior field, is sensed in a higher harmonic of the base frequency.
This cannot be done with a linear (frequency dependent) or linearized (small-signal analysis)
study that are also provoded by COMSOL. You would need to simulate the device time-dependent just 
like our library model of the e-core transformer with a nonlinear core.
ch.comsol.com/model/e-core-transformer-using-multi-turn-coil-domains-14123
With best regards
Sven Friedel                                                
                            Hi Mohammed,
for this purpose you should use magnetic fields with time-dependent analysis.
As far as I remember from my studies a fluxgate magnetometer uses the second harmonic 
generation. A magnetically nonlinear material is driven into saturation and the actual
measurement signal, proportional to the exterior field, is sensed in a higher harmonic of the base frequency.
This cannot be done with a linear (frequency dependent) or linearized (small-signal analysis)
study that are also provoded by COMSOL. You would need to simulate the device time-dependent just 
like our library model of the e-core transformer with a nonlinear core.
https://ch.comsol.com/model/e-core-transformer-using-multi-turn-coil-domains-14123
With best regards
Sven Friedel                        
                                                
                                                                                                            
                                             
                                            
                            
                                                                                        
                                Mohammed Thameemul Ansari
                                                                                                                                                 
                            
                         
                                                
    
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                                                Posted:
                            
                                1 decade ago                            
                            
                                24 mars 2015, 22:47 UTC−4                            
                        
                        
                                                    Hello Sven Friedel 
Thank you very much for your reply. You are right i was using the same library model to compute my results but my problem is in sensitivity. How should i measure the sensitivity of the sensor? According to the theory i have to plot the hysteresis loop to justify my answer. Do you know any other method to calculate the sensitivity of the sensor? Would you please suggest me some way to find this out? Thanks in advance.                                                 
                                                
                            Hello Sven Friedel 
Thank you very much for your reply. You are right i was using the same library model to compute my results but my problem is in sensitivity. How should i measure the sensitivity of the sensor? According to the theory i have to plot the hysteresis loop to justify my answer. Do you know any other method to calculate the sensitivity of the sensor? Would you please suggest me some way to find this out? Thanks in advance.                         
                                                
                                                                                                            
                                             
                                            
                            
                                                                                        
                                Sven Friedel
                                                                                                                                                    COMSOL Employee
                                                         
                            
                                                                                                                                                
                         
                                                
    
        Please login with a confirmed email address before reporting spam
     
    
 
                                                Posted:
                            
                                1 decade ago                            
                            
                                25 mars 2015, 10:54 UTC−4                            
                        
                        
                                                    Well, I would define the sensitivity probably as \delta V / \delta B. You might want to derive a curve  V(B) measuring the amplitude of the fully developed time dependent solution of the voltage V and the external flux density B.  After that,  you could differentiate this curve for instance with a spreadsheet program.
Sven                                                 
                                                
                            Well, I would define the sensitivity probably as \delta V / \delta B. You might want to derive a curve  V(B) measuring the amplitude of the fully developed time dependent solution of the voltage V and the external flux density B.  After that,  you could differentiate this curve for instance with a spreadsheet program.
Sven                         
                                                
                                                                                                            
                                             
                                            
                            
                                                                                        
                                Mohammed Thameemul Ansari
                                                                                                                                                 
                            
                         
                                                
    
        Please login with a confirmed email address before reporting spam
     
    
 
                                                Posted:
                            
                                1 decade ago                            
                            
                                8 avr. 2015, 01:59 UTC−4                            
                        
                        
                                                    Hello sir 
According to my model i have to wound a excitation coil in both sides of the toroidal core which should be connected together. Would you please suggest me how to connect this two coil? Another issue is to coupling with circuit. Therefore, i have to couple the sense/secondary coil with the band pass filter circuit. So my doubt here is how to define the nodes?  Here, i have attached the circuit photo.                                                 
                                                
                            Hello sir 
According to my model i have to wound a excitation coil in both sides of the toroidal core which should be connected together. Would you please suggest me how to connect this two coil? Another issue is to coupling with circuit. Therefore, i have to couple the sense/secondary coil with the band pass filter circuit. So my doubt here is how to define the nodes?  Here, i have attached the circuit photo.                         
                                                
                        
                                                
                                                                                                            
                                             
                        
                        
                            
                                                                                        
                                Sven Friedel
                                                                                                                                                    COMSOL Employee
                                                         
                            
                                                                                                                                                
                         
                                                
    
        Please login with a confirmed email address before reporting spam
     
    
 
                                                Posted:
                            
                                1 decade ago                            
                            
                                8 avr. 2015, 11:45 UTC−4                            
                        
                        
                                                    Please send your COMSOL model - if you do not want to share it in the forum feel free to contact us diorectly through support@comsol.com.
Best regards,
Sven Friedel                                                
                                                
                            Please send your COMSOL model - if you do not want to share it in the forum feel free to contact us diorectly through support@comsol.com.
Best regards,
Sven Friedel