BS CECC 25000:1977

Foreword
Preface
SECTION 1 - SCOPE
SECTION 2 - GENERAL
2.1 Order of precedence
2.2 Related documents
2.3 Units, symbols and terminology
2.3.1 General
2.3.2 Multiples and sub-multiples of units
2.3.3 Letter symbols
2.3.4 Type of core
2.3.5 Inductance factor
2.3.6 Variability
2.3.7 Temperature factor
2.3.8 Temperature coefficient
2.3.9 Disaccommodation
2.3.10 Disaccommodation coefficient
2.3.11 Disaccommondation factor
2.3.12 Magnetic conditioning
2.3.13 Instability
2.3.14 Instability factor
2.3.15 Parallel reactance coefficient
2.3.16 Parallel resistance coefficient
2.3.17 Vanishingly low value of flux density
2.4 Standard and preferred values
2.4.1 Dimensions
2.4.2 Inductance factor
2.5 Effective parameters
SECTION 3 - QUALITY ASSESSMENT PROCEDURES
3.1 Primary stage of manufacture
3.2 Specimen
3.3 Inspection for qualification approval
3.4 Quality conformance inspection
3.5 Delayed delivery
3.6 Certified test records
SECTION 4 - TEST AND MEASUREMENT CONDITIONS
4.1 Standard measuring frequencies
4.2 Environmental conditions
4.2.1 General
4.2.2 Ambient temperature
4.3 General precautions for methods involving
        permeability measurements
4.3.1 Parameters involved
4.3.2 Relation to practice
4.3.3 Mounting of cores consisting of more than one
        part
4.4 General precautions for loss measurement at low
        flux density
4.4.1 Contributory losses
4.4.2 Mounting
4.5 Magnetic conditioning
4.5.1 Object
4.5.2 Principles of the methods
4.5.3 Procedure for the electrical method
4.5.4 Procedure for the thermal method
4.6 Inductance measurement
4.6.1 Object
4.6.2 Means of coupling
4.6.3 Absolute measurement
4.6.4 Relative measurement
4.7 Disaccommodation
4.7.1 Object
4.7.2 Principle of the method
4.7.3 Specimens
4.7.4 Timing device
4.7.5 Measuring procedure
4.7.6 Calculation
4.8 Variation of permeability with temperature
4.8.1 Object
4.8.2 Principle of the method
4.8.3 Specimens
4.8.4 Temperature cycling device
4.8.5 Timing device
4.8.6 Measuring procedure
4.8.7 Calculation
4.9 Range of inductance adjustment
4.9.1 Object
4.9.2 Terminology
4.9.3 Principle of the measurement
4.9.4 Specimens
4.9.5 Measuring procedure
4.9.6 Calculation
4.10 Losses at low flux density
4.10.1 Object
4.10.2 Specimens
4.10.3 Means of coupling
4.10.4 Measurement of residual plus eddy current loss
4.10.5 Measurement of the hysteresis loss
4.10.6 Reference methods
4.11 Mechanical testing
4.11.1 Compression load
4.11.2 Adjusting device
4.12 Third harmonic distortion
4.12.1 Object
4.12.2 Terminology
4.12.3 Principle of the measurement
4.12.4 Specimens
4.12.5 Measuring instruments
4.12.6 Measuring procedure
4.12.7 Calculation
4.13 Magnetic shock sensitivity
4.13.1 Object
4.13.2 Terminology
4.13.3 Principle of the measurement
4.13.4 Specimens
4.13.5 Pulse generator
4.13.6 Timing device
4.13.7 Measuring procedure
4.13.8 Calculation
4.14 Contribution of the adjusting device to the core
        instability
4.14.1 Object
4.14.2 Terminology
4.14.3 Principle of the method
4.14.4 Specimens
4.14.5 Conditioning chamber
4.14.6 Measuring procedures
4.14.7 Calculation
4.15 Influence of a static magnetic field
4.16 Total core loss
4.16.1 Object
4.16.2 Principles of measurement
4.16.3 Specimens
4.16.4 Measuring coil
4.16.5 Measuring equipment
4.16.6 Measuring procedure
4.16.7 Calculation
4.17 (Effective) Amplitude permeability
4.17.1 Object
4.17.2 Principle of measurement
4.17.3 Specimens
4.17.4 Measuring coil
4.17.5 Measuring equipment
4.17.6 Measuring procedure
4.17.7 Calculation
Appendices
I. Damped oscillation method for loss measurement
        calibration
II. Transmission method for loss measurement
        calibration
III. Examples of circuits for the measuring total core
        loss
        (1) Multiplying voltmeter method
        (2) Bridge method
        (3) Oscilloscope method
        (4) Non-reactive resistance
IV. Examples of circuits for the measurement of the
        (effective) amplitude permeability
        (1) Circuit using measuring coil with a single
             winding
        (2) Circuit using a double wound measuring coil

Terminology and procedure applicable to the entire family of inductor and transformer cores for telecommunications.