IEC 61631 pdf download Test method for the mechanical strength of cores made of magnetic oxides
This International Standard specifies a test method for the mechanical strength of cores madeof magnetic oxides.This test method is suitable for most of the E-cores,ETD-cores andl-cores but other core types such as U-cores could be tested according to a derived methodagreed by the parties concerned.
2 Normative references
The following referenced documents are indispensable for the application of lEC 61631.Fordated references,only the edition cited applies. For undated references, the latest edition ofthe referenced document (including any amendments) applies.
IEC 61246:1994，Magnetic oxide cores(E-cores) of rectangular cross-section and associatedparts – Dimensions
EN 10002-2:1992，Tensile testing of metallic materials – Part 2: Verification of the forcemeasuring system of the tensile testing machine
ISO 4677-1:1985,Atmospheres for conditioning and testing – Determination of relative humidity -Part 1: Aspirated psychrometer method
ISO 4677-2:1985,Atmospheres for conditioning and testing – Determination of relative humidity -Part 2: Whirling psychrometer method
For the purpose of this International Standard, the following definition applies.
the maximum recorded force at the instant of fracture of a magnetic oxide core when it isloaded in bending
4.1 Test core support and loading wedge
Test cores shall be supported on free moving roller bars or on a flat support depending on theirsize (see 6.2).The loading wedge and the roller bars or the flat support shall be made ofhardened steel with a hardness of 40 HRC to 60 HRC.The loading wedge and the roller barsshall have a radius of 2 mm.The loading wedge shall be connected to a device for measuringand recording the load applied.
The testing device shall be a mechanical testing machine capable of applying a force to theloading wedge high enough to break the test core. The machine shall be capable of applyingthe force at a constant loading-rate.The machine shall be equipped with a device for recordingthe peak load applied to the test core.The accuracy of the machine shall be in accordance withEN 10002-2,Grade 1 (accuracy 1 % of the indicated load).Force calibration of the machineshall be checked in accordance with EN 10002-2.
4.3 Humidity measuring device A humidity measuring device shall be as specified in ISO 4677-1 or ISO 4677-2 and shall be capable of measuring relative humidity to an accuracy of ±2 %.
5 Test cores
The test cores shall be selected as agreed between the parties concerned. They may be machined to the specified, dimensions, because any machined surface plays an important role in the mechanical strength (see Introduction).