State Scientific Center of the Russian Federation
        

      


      

        

          

		
        


        

          

            

              
20.01.2026

              
Вторник

            


            
14 : 01 : 30, 123

          


          
State Scientific Center of the Russian Federation

        


        

          

            

              
            

          


          
    
            
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ГЭТ 12-2021 (НИЛ 2205)

	    

	


		

							

					
Standard name:


					
    
						
  • ГЭТ 12-2025 State Primary Standard of Units of Magnetic Induction, Magnetic Flux, Magnetic Moment and Magnetic Induction Gradient
    • 
					

				

										

					
Type of measurement:


					
    
						
  • Measurements of electrical and magnetic quantities
    • 
					

				

										

					
Structural division: name НИО\НИЛ:


					
    
						
  • Research Laboratory of State Standards in the Field of Magnetic Measurements
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Guardian Scientist:


					
    
						
  • Belyakov Denis Igorevich, Candidate of Technical Sciences.
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Year of creation:


					
    
						
  • 2012
    • 
					

				

			
							

					
Year of re-confirmation:


					
    
						
  • 2025
    • 
					

				

					


					

				

					
Operating principle:


					
    
						
  • The state primary standard of units of magnetic quantities assumes the reproduction of units of magnetic induction B of a constant (=) and alternating (≈) field, magnetic flux Ф, magnetic moment Pm and magnetic induction gradient Gm based on the following equations:
    


    Where ω is the circular frequency of magnetic resonance; 
γНе4 is the gyromagnetic ratio of 4Не atoms; 
KB is the geometric constant of the reference magnetic induction coil;
KФ is the geometric constant of the reference magnetic flux coil;
Km is the geometric constant of the reference magnetic moment coil;
KG is the geometric constant of the reference magnetic induction gradient coil; 
I is the current in the reference coil.

    

    Reproduction and transmission of the unit - Tл - in the region of constant fields in a country laboratory is carried out by two independent methods: the first, on the basis of the gyromagnetic ratio γHe4 of helium-4 atoms and the second, according to the constant KВ of the standard quartz 4-section measure of magnetic induction (C4-2), obtained through the linear parameters of the winding, as well as the current I passed through its winding.

    

    
To control the T/A value, the KB═ constant is determined by the ratio of the magnetic induction (MI) reproduced by the C4-2 standard to the electric current passing through its winding. Current I is measured by comparing the voltage drop across a 1 Ω standard resistor connected in series with the MI standard winding with the standard voltage.

    

    
Reproduction and transmission of the T value in the range of 1∙10-8–1∙10-3 T is carried out using a constant magnetic field comparator with full automatic compensation of the Earth's magnetic field by means of a reference three-component comparator-measure of constant field magnetic induction ETMK.

    

    The same measuring system carries out the transfer of the T/A size on direct current, i.e. the determination of the conversion constants (constant) – KB0 of MI measures, applied both on direct and alternating current.

    

    
Transfer of the unit of magnetic induction in "medium" and "strong" magnetic fields, in the range of 1∙10-3– 1.5 T, is accomplished using the KKMI reference subcomplex.

    

    The KF constants of the КС-4 reference measure (solenoid) are determined by two independent methods: by calculation using its linear dimensions and by the Rf method.

    

    
The constants of the dependence of KB≈ of the reference measure (solenoid) КС-4 on the frequency in the range from 1 Hz to 20 kHz are determined by calculation through its linear dimensions, which have a primary (KB≈) and secondary (KF) windings, which together represent the primary converter of reference measures of magnetic flux and magnetic induction.

    

    The value of the constant KB= of the КС-4 solenoid on direct current is determined by comparison with the C4-2 standard measure using a standard helium-cesium magnetometer.
    

    
Based on the КС-4 reference solenoid, the transfer of the sizes Bb/A and Bb/Tl [(A∙m2)/A] on direct current is carried out by means of the reference comparator of magnetic flux and magnetic moment measuring instruments EKPM. On alternating current up to 20 kHz, together with the КС-4 reference measure, the reference comparator of alternating field magnetic induction EKPP is used for transferring the size Tl/A to measures of alternating field magnetic induction, as well as to induction converters and measures of magnetic moment of the size Bb/Tl

    

    
The constant KG is determined by calculation using the linear dimensions of the ESGMI-1 reference magnetic induction gradient solenoid. Magnetic induction with a given gradient is reproduced by passing a direct electric current through the ESGMI-1 winding.

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Composition of the standard:


					
The primary standard consists of a set of the following measuring instruments:


    

  • EGM 1 and EGM 2 Standard Helium-Cesium Magnetometers;
    • 

  • C4-2 and ESTV Standard Quartz Magnetic Induction Solenoids of Constant Field;
    • 

  • КС-4 Standard Quartz Solenoid of Magnetic Induction, Magnetic Flux, and Magnetic Moment;
    • 

  • EKMM-1 Standard Quartz Magnetic Moment Measure (Coil);
    •  

  • ESGMI-1 Standard Quartz Gradient Solenoid of Magnetic Induction;
    • 

  • Эталонная трехкомпонентная мера - компаратор средств измерений магнитной индукции постоянного поля ЭТМК;
    •  

  • A standard measuring unit for reproducing and transmitting the unit of magnetic induction of an alternating field УИЭПП;
    • 

  • Reference comparator for magnetic flux and magnetic moment measuring instruments ЭКПМ;
    • 

  • Quantum comparator of magnetic induction of a constant field ККМИ.
    • 


				

			

			




	

		

			
Main metrological characteristics


			

				

  

Physical quantity
Range
Frequency, Hz
Units reproduction and transmission errors
Result error




    RMS (n=10)
    NSP (P=0.99)
    Sco
  

  

    Magnetic induction (MI)
    
      1⋅10-8–1⋅10-6 T

      1⋅10-6–1⋅10-3 T

      1⋅10-3–1.5 T
    		
    
      0
    
    
      0.10 nTl

      2⋅10-6 - 5⋅10-8

      7⋅10-7- 3⋅10-6
    		
    
      0.11 nT

      7.5⋅10-5 – 6⋅10-7

      2⋅10-6-1.2⋅10-5
    		
    
      0.15 nT

      3⋅10-5 - 2⋅10-7

      1⋅10-6-5⋅10-6
    		
  

  

    
      1⋅10-6–5⋅10-4 T
    
    
      1 -400000
    
    
      3∙10-3 – 5∙10-4
    
    
      2.3∙10-2 –9∙10-4
    
    8.4∙10-3–6∙10-4
  

  


Magnetic Flux (MF)


5⋅10-6 - 3⋅10-2 Wb

0
1⋅10-2 –5⋅10-6
1⋅10-3– 4.3⋅10-5
1⋅10-2–1.5⋅10-5


  

Magnetic moment (MM)
3⋅10-4 – 20 A⋅m2
0

5⋅10-3 - 1⋅10-5


3⋅10-3 –1.8⋅10-4


5⋅10-3 - 6⋅10-5





    
      Gradient MI (GMI)
    
    
      1⋅10-5-1⋅10-1 T/m
    
    
      0
    
    
      1⋅10-2 –1⋅10-3
    
    
      5⋅10-4
    
    
      1⋅10-2–1⋅10-3
    
  

  


Angle between the magnetic axes of the MI units


90±0.1 arc degrees


0


2 arc seconds


5 arc seconds


3 arc seconds



  


MI to Current Ratio


1⋅10-6 - 1⋅10-2 T/A


0

1-20000

20000 –400000


2⋅10-6 - 5⋅10-8

1⋅10-3 - 7⋅10-5

1⋅10-3 – 7⋅10-5
    		
    
      3.6⋅10-6–1.8⋅10-6

      1⋅10-3 –1.5⋅10-4

      1⋅10-3 –1.5⋅10-4
    		
    
      2.3⋅10-6–6⋅10-7

      1⋅10-3 –1⋅10-4

      1.1⋅10-3–9⋅10-5
    		
  

  


Magnetic Field to Current Ratio


1⋅10-4 -1⋅10-2 Wb/A


0


3⋅10-3 - 1⋅10-5


1⋅10-3 –4.3⋅10-5


3⋅10-3–1.5⋅10-5






MP to MI ratio [MM to current ratio, (A⋅m2)/A]


1⋅10-2 - 20 Wb/T


0

20-20000


1⋅10-3 - 4⋅10-5

1⋅10-3 - 2⋅10-5


      3⋅10-4-1⋅10-4

      5⋅10-4 - 1.5⋅10-4
    		
    
      1⋅10-3-6⋅10-5

      1⋅10-3-6⋅10-5
    		
  

  

    
      GMI to current ratio
    
    
      1⋅10-3-1⋅10-1 Tl∙m-1∙A-1
    
    
      0
    
    
      5⋅10-3-1⋅10-3
    
    
      1.7⋅10-4
    
    
      5⋅10-3–1⋅10-3




			


			

		

	




	

					

				

					
Verification diagram:


					
    
						
  • Heads the interstate state verification scheme for measuring instruments of magnetic induction, magnetic flux, magnetic moment and magnetic induction gradient ГОСТ 8.030-2025.
    • 
					

				

			

		
					

				

					
Scope of application:


					
    

  • Fundamental science, in the search for the permanent electric dipole moment of the neutron, etc.;
    •  

  • Planetary geophysics, the study of the physical nature of terrestrial magnetism, earthquake prediction;
    •  

  • Aeronomy, the study of solar-terrestrial relations and their influence on radio wave propagation;
    •  

  • The study of magnetic fields in near and deep space;
    •  

  • Archaeology and paleontology;
    • 

  • Exploratory geophysics, in mineral exploration and resource assessment;
    •  

  • Search for hidden technical objects for pipeline routing, military equipment, security purposes, etc.;
    •  

  • Advanced weapons, military, and special equipment;
    •  

  • Solutions to problems of contactless determination of the quality and technical parameters of industrial products;
    • 

  • Solving electromagnetic compatibility issues;
    •  

  • Implementing maritime and aerospace navigation;
    •  

  • Resolving environmental issues related to the impact of magnetic fields of energy-intensive technical objects and hypogeomagnetic fields on humans;
    •  

  • Studying human magnetic fields and their impact on humans for medical diagnostic purposes.
    • 


				

			

		
					

				

					
Results of applying the standard:


					
The improvement of the primary standard ГЭТ 12 increases the level of uniformity of magnetic measurements by improving the range of the highest level of the state verification scheme for modern measuring instruments for the induction of constant and alternating magnetic fields, magnetic flux, magnetic moment and magnetic induction gradient used in various areas of the country's activities, as well as by creating conditions for the participation of the State Scientific Research Institute of the Russian Federation in key comparisons.

				

			

		
					

				

					
The total number of measuring instruments traceable to ГЭТ 12-2021:


					
Tens of thousands.

				

			

			



	

		

			

				

					
Ensuring the uniformity of measurements, participation in the CIPM MRA program:


					

						

  
    

      Quantity
      Measurand Minimum value
      Measurand Maximum value
      Unit
      Expanded uncertainty Maximum value
      Coverage factor
      Type of uncertainty
      NMI Service Identifier
    

  
  
    

      Magnetic fields below 50 kHz: DC magnetic flux density
      1.0E-7
      1.0E-5
      T
      0.05
      2.0
      Absolute
      VNIIM/205
    

    

      Magnetic fields below 50 kHz: DC magnetic flux density
      1.0E-5
      1.0E-4
      T
      0.03
      2.0
      Absolute
      VNIIM/206
    

    

      Magnetic fields below 50 kHz: DC magnetic flux density
      1.0E-4
      0.001
      T
      0.3
      2.0
      Absolute
      VNIIM/207
    

    

      Magnetic fields below 50 kHz: magnetic flux
      1.0E-5
      0.01
      Wb
      0.005
      2.0
      Relative
      VNIIM/203
    

    

      Magnetic fields below 50 kHz: magnetic flux per unit current
      1.0E-4
      0.01
      Wb/A
      0.001
      2.0
      Relative
      VNIIM/204
    

    

      Magnetic fields below 50 kHz: DC magnetic flux density
      0.001
      0.1
      T
      2.0E-4
      2.0
      Relative
      VNIIM/208
    

    

      Magnetic fields below 50 kHz: AC magnetic flux density
      1.0E-7
      0.001
      T
      0.002
      2.0
      Relative
      VNIIM/211
    

    

      Magnetic fields below 50 kHz: turn area
      0.001
      0.1
      Wb/T
      0.01
      2.0
      Relative
      VNIIM/213
    

    

      Magnetic fields below 50 kHz: turn area
      0.1
      20.0
      Wb/T
      0.001
      2.0
      Relative
      VNIIM/214
    

    

      Magnetic fields below 50 kHz: DC magnetic flux density per unit current
      1.0E-5
      0.001
      T/A
      1.0E-5
      2.0
      Relative
      VNIIM/215
    

    

      Magnetic fields below 50 kHz: DC magnetic flux density per unit current
      0.001
      0.05
      T/A
      1.0E-4
      2.0
      Relative
      VNIIM/216
    

    

      Magnetic fields below 50 kHz: AC magnetic flux density per unit current
      1.0E-5
      0.001
      T/A
      0.003
      2.0
      Relative
      VNIIM/217
    

    

      Magnetic fields below 50 kHz: magnetic field gradient
      1.0E-6
      3.0
      T/m
      0.03
      2.0
      Relative
      VNIIM/218
    

    

      Magnetic fields below 50 kHz: magnetic field gradient per unit current
      0.001
      1.0
      T/(Am)
      0.015
      2.0
      Relative
      VNIIM/219
    

    

      Feebly magnetic, paramagnetic and diamagnetic material: DC magnetic susceptibility
      1.0E-7
      0.01
      -
      0.03
      2.0
      Relative
      VNIIM/435
    

    

      Hard magnetic material: magnetic moment
      0.001
      20.0
      Am2
      0.01
      2.0
      Relative
      VNIIM/441
    

  

					


					

				

			

		

	

	

		

			

				

					
Unique technical installations as part of the standard:


					
    

  • Reference helium-cesium magnetometers ЭГМ 1 и ЭГМ 2;
    • 

  • A reference three-component measure - a comparator of measuring instruments for the magnetic induction of a constant field ЭТМК;
    •  

  • A standard measuring unit for reproducing and transmitting the unit of magnetic induction of an alternating field УИЭПП;
    • 

  • Reference comparator for magnetic flux and magnetic moment measuring instruments ЭКПМ;
    • 

  • Quantum comparator of magnetic induction of a constant field ККМИ.
    • 


				

			

		

	



	

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