GOST 12119.2-98
GOST 12119.2−98 electrotechnical Steel. Methods for determining magnetic and electrical properties. Measurement method of magnetic induction in Permeameter
GOST 12119.2−98
Group B39
INTERSTATE STANDARD
Electrotechnical steel
METHODS FOR DETERMINING MAGNETIC AND ELECTRICAL PROPERTIES
Measurement method of magnetic induction in Permeameter
Electrical steel. Methods of test for magnetic and electrical properties.
Method for measurement of magnetic induction in permeameter
ISS 77.040.20
AXTU 0909
Date of introduction 1999−07−01
Preface
1 DEVELOPED by the Russian Federation, the Interstate technical Committee for standardization MTK 120 «steel Products from ferrous metals and alloys"
INTRODUCED by Gosstandart of Russia
2 ADOPTED by the Interstate Council for standardization, Metrology and certification (minutes N 13 dated 28 may 1998)
The adoption voted:
| The name of the state |
The name of the national authority for standardization |
| The Republic Of Azerbaijan |
Azgosstandart |
| The Republic Of Armenia |
Armastajad |
| The Republic Of Belarus |
Gosstandart Of Belarus |
| Kyrgyz Republic |
Kyrgyzstandart |
| Russian Federation |
Gosstandart Of Russia |
| The Republic Of Tajikistan |
Tajikistandart |
| Turkmenistan |
The main state inspection of Turkmenistan |
| The Republic Of Uzbekistan |
Standards |
| Ukraine |
Gosstandart Of Ukraine |
3 Resolution of the State Committee of the Russian Federation for standardization and Metrology dated December 8, 1998 N 437 inter-state standard GOST 12119.2−98 introduced directly as state standard of the Russian Federation from July 1, 1999
4 REPLACE GOST 12119−80 in section 2
5 REISSUE
1 Scope
This standard specifies a method of measuring magnetic induction by the magnetic field 1000−30000 vehicles in the Permeameter.
2 Normative references
The present standard features references to the following standards:
GOST 8711−93 Devices showing analog electrical measuring direct action and auxiliary parts to them. Part 2. Special requirements for ammeters and voltmeters
GOST 12119.0−98 electrotechnical Steel. Methods for determining magnetic and electrical properties. General requirements
GOST 20798−75 Action of mutual induction. General specifications
GOST 21427.2−83 cold-rolled isotropic electrotechnical Steel sheet. Specifications
GOST 23737−79 measure of electrical resistance. General specifications
3 General requirements
General requirements for test methods — according to GOST 12119.0.
Terms used in this standard — GOST 12119.0.
4 Preparation of samples for testing
The samples are made from strips of lengths from 400 to 600 mm, a width (30,0±0,2) mm. Strip of the sample should not differ from each other in length by more than ±0,2%. The cross-sectional area of the samples should be from 0.5 to 3.0 cm.
5 Used equipment
5.1 Install. Installation diagram is shown in figure 1.
Figure 1 — Schema for measurement Permeameter
Figure 1 — Schema for measurement Permeameter
5.1.1 Ammeter to measure DC current and subsequent determination of the magnetic field must have a measurement range of 15 mA to 15 A, accuracy class not less than 0.2 according to GOST 8711.
Use a DC voltmeter with a resistor.
5.1.2 the Ballistic galvanometer to measure the magnetic flux must have the period of natural oscillations of at least 15; intermittent, close to critical; sensitivity of at least 500 cases./MVB; the category of the constancy of the zero position — no more than one.
Use of ballistic galvanometer with a shunt, magneto or electronic integrating fluxmeter to measure magnetic flux of 0.1 to 10.0 MVB with an accuracy within ±1%; webartery with voltage dividers to expand the limits of measurement and (or) receiving of the samples is numerically equal to the amplitude of the magnetic induction in the sample.
5.1.3 Resistor for modulating the current in interval from 2 mA to 15 A with a resolution of 0.1%.
5.1.4 resistance boxes ,
,
to adjust the sensitivity and the mode of the galvanometer should have a range from 0.1 Ohms to 10 ohms, accuracy class not less than 0.2 churchyard 23737.
5.1.5 Coil for calibrating the ballistic galvanometer must have coefficient of mutual inductance from 1 mH to 10, accuracy class not less than 0.2 according to GOST 20798.
5.1.6 Permeameter for the magnetization must have a coil I, inside which is placed the test sample, and the yoke, closing the sample from two sides.
5.1.6.1 II Coil Permeameter for measuring the magnetic field intensity must be applied to the surface of the specimen and have a thickness of 5 mm, a width of (26±1) mm, a constant coil
of at least 0.1 m
, defined with an accuracy to within ±1%. The resistance of the winding coil should be less than the external critical resistance galvanometer or a maximum external resistance of the fluxmeter.
5.1.6.2 III Coil Permeameter for measuring the magnetic induction shall be evenly wound on insulated Central part of the sample.
5.1.6.3 Coil II and III shall be adjacent; the number of turns are selected so that the reading of the galvanometer or fluxmeter was not less than 40% of the upper limit of the measurement.
5.1.7 the power Source for magnetization of the sample should provide a constant output voltage of at least 20V, the measurement of the magnetizing current is not more than 0.2% per minute, the ratio of the amplitude of the variable component of the output voltage to the DC component is not more than 0.05%. In magnetic field of more than 5 vehicles allowed increase in the ratio of 0.1%. You may use a DC regulator.
5.1.8 Switches and
must be designed for a maximum current of 15 A.
5.1.9 Switches and
should have a resistance not more than 0.02 Ohms in the closed position and thermoelectric power of not more than 1 mV.
6 Preparation for measurements
6.1 cross-sectional Area of the sample , m
, is calculated by the formula
where is the mass of sample, kg;
— band length of the sample, m;
— density of material, kg/m
.
Material density , kg/m
, choose according to the Annex 1 GOST 21427.2 or calculated by the formula
where and
— mass fraction of silicon and aluminum, %.
6.2 measurement Uncertainty of the sample mass should not go beyond ±0.2%, the length of strips is ±0,2%.
6.3 Before the measurement should be carried out calibration of ballistic galvanometer to determine the permanent and
the WB/del. The calibration is carried out on the installation (see figure 1) in the absence of the test sample.
6.3.1 resistance in the circuit of the galvanometer in the calibration and subsequent measurement of the magnetic induction in the sample should be constant. The current in the winding I of the coil must be such that the reading of the galvanometer ranged from 20 to 50% of the length scale with the zero mark in the middle. The deviation of the pointer of the galvanometer must be in the same direction as in the definition of magnetic quantities.
6.3.2 in determining the constant of the galvanometer , WB/cases., galvanometer connected to the coil II of the Permeameter.
Switches ,
and
put in position
, the key
closes. In the coil I coil
sets a predetermined value of current
, and upon opening the circuits of the switches
and
determine the indication of the galvanometer
, del.
The operation is repeated not less than three
time.
6.3.3 in determining the constant of the galvanometer , WB/cases., galvanometer connected to the coil III of the Permeameter.
The switches and
put in a position
, the switch
is in the on position
, the key is
short and perform operations in accordance with 6.3.2
.
6.3.4 Constant of a ballistic galvanometer and
, WB/cases., calculated as an arithmetic average of the constant of the galvanometer
, WB/cases., received at least three values of current for each coil of the Permeameter.
6.3.5 the Constant of the galvanometer to a predetermined value of current , WB/cases., calculated by the formula
where — coefficient of mutual inductance coil
, RH;
— the arithmetic average of the readings of the galvanometer
, as defined, as specified in 6.3.2 and 6.3.3;
— the specified current value A.
When using the galvanometer with a shunt constant and
, WB/cases., should be determined for each value of the coefficient of shunting
.
6.4 When using the fluxmeter from the unit exclude: switch , coil
and resistors
,
,
(see figure 1).
6.5 the Value of the magnetizing current , And the value of magnetic field intensity
, A/m, is calculated by the formula
where — length of the specimen inside the Permeameter, m;
the number of turns of the coil I coil Permeameter.
6.6 the Indication of the galvanometer , del., value of magnetic field intensity
, A/m, is calculated by the formula
where 
— continuous coil II Permeameter, m
;
— the constant of the galvanometer determined as specified in 6.3, WB/del.
6.7 When using rectilinear scales introduce the amendment , del., calculated according to the formula
where is the distance between the mirror galvanometer and scale, the scale marks.
In the formula (5) the value is replaced by the value of
del., calculated according to the formula
6.8 Indication of fluxmeter , WB, value of magnetic field intensity
, A/m, is calculated by the formula
7 procedures for measuring
7.1 Measurement of magnetic induction in the specimen based on the pulse-induction method.
7.2 upon the installation (see figure 1) the switch is put in position
, the switch
is in the on position
; set the magnetizing current
, And corresponding to the specified lowest value of the magnetic field; carry out switching of the switch
; disconnect an key
; change the direction of the current switch
and determine the indication of the galvanometer
, de
L.
7.3 If the difference of the measured from the calculated according to the formula (5) at the bottom of the key
, increase the flow
, and repeat the operations to determine the readings of the galvanometer to obtain the desired values
, del.
7.4 in the measurement of the magnetic induction switch is put in position
and determine the indication of the galvanometer
, del.
7.5 Set the magnetizing current corresponding to the larger given value of the magnetic field and repeat the operation 7.2−7.4.
7.6 in the measurement of magnetic induction with the help of a fluxmeter carry out the operations specified in 7.2 to 7.5.
8 Rules for processing results of measurements
8.1 Magnetic induction , T, measured with a galvanometer, is calculated by the formula
where is the constant of the galvanometer determined as specified in 6.3, WB/del.;
— the reading of the galvanometer, del.;
— number of turns in the coil III of the Permeameter;
the cross — sectional area of specimen, m
.
8.2 When using a straightforward scale of the galvanometer is introduced the amendment , del., calculated according to the formula (6).
In the formula (9) the value of del., replace the value of
del., calculated according to the formula
8.3 Magnetic induction , T, measured using the fluxmeter, is calculated by the formula
where — reading fluxmeter, WB.
8.4 the measurement Error of the magnetic induction should not go beyond ±1,5%.
The text of the document is verified by:
the official publication of the
Electrotechnical steel.
Specifications. Methods of analysis:
SB. Standards. -
M.: IPK Publishing house of standards, 2003
