IEC 60068-2-27 offers a customary approach for opting for the power of a specimen to resist particular severities of non-repetitive or repetitive shocks. the aim of this try is to bare mechanical weak point and/or degradation in designated performances, or collected harm or degradation because of shocks. at the side of the suitable specification, this can be utilized in a few circumstances to figure out the structural integrity of specimens or as a method of quality controls. This try is essentially meant for unpackaged specimens and for goods of their shipping case while the latter could be thought of to be a part of the specimen. If an merchandise is to be confirmed unpackaged, it really is often called a attempt specimen. in spite of the fact that, if the object is packaged, then the thing itself is often called a product and the article and its packaging jointly are known as a try out specimen. while utilized in conjunction with IEC 60068-2-47, this regular can be utilized for checking out packaged items. This chance used to be incorporated within the 2005 model of IEC 60068-2-47 for the 1st time. This commonplace is written when it comes to prescribed pulse shapes. suggestions for the choice and alertness of those pulses is given in Annex A and the features of the various pulse shapes are mentioned in Annex B. anyplace attainable, the try severity and the form of the surprise pulse utilized to the specimen might be resembling to breed the results of the particular delivery or operational setting to which the specimen could be subjected, or to fulfill the layout standards if the item of the try is to evaluate structural integrity (see Clauses A.2 and A.4). For the needs of this attempt, the specimen is often fastened to the fixture or the desk of the surprise trying out computing device in the course of trying out. the main adjustments in regards to the former version concern:
- the merging of IEC 60068-2-29 into this version of IEC 60068-2-27; half 2-29 may be withdrawn once this variation is published;
- the creation of soppy packaged specimens as outlined within the IEC advert hoc operating staff rfile agreed in Stockholm:2000.
Has the prestige of a simple safeguard e-book in keeping with IEC consultant 104.
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Additional info for IEC 60068-2-27 ed4,0 Environmental testing - Part 2-27: Tests - Test Ea and guidance: Shock
Un guide pour la sélection et l’application de ces impulsions est donné à l’Annexe A et les caractéristiques des différentes formes d’impulsion sont exposées à l’Annexe B. 4). Pour les besoins de cet essai, le spécimen est toujours monté sur le bâti de fixation ou sur la table de la machine d’essai au choc pendant l’épreuve. NOTE Le terme «machine d’essai au choc» est utilisé partout dans cette norme mais d’autres moyens d’appliquer des formes d’ondes ne sont pas exclus. L’une des responsabilités d’un comité d’études consiste, le cas échéant, à utiliser les publications fondamentales de sécurité dans le cadre de l’élaboration de ses publications.
Although there is some over-testing with regard to the initial spectrum, there is a considerable degree of overlap of these spectra. 5 – Spectrum of a final-peak saw-tooth 300 m/s 2 , 18 ms pulse compared with the spectra of 200 m/s 2 half-sine pulses with durations between 3 ms and 20 ms Copyright International Electrotechnical Commission Provided by IHS under license with IEC No reproduction or networking permitted without license from IHS Not for Resale – 36 – 60068-2-27 © IEC:2008 Annex C (informative) Comparison between impact tests Test Ec: Rough handling shocks, primarily for equipment-type specimens (IEC 60068-2-31)  Intended to assess the effects of knocks or jolts likely to be received primarily by equipment-type specimens during repair work or rough handling on a table or bench.
Sévérité m/s 2 150 300 500 Durée gn 15 30 50 Forme d’impulsion Utilisation composant ms 11 18 11 Demisinusoïde Dents-de-scie à pointe finale Trapèze Essai fondamental pour la robustesse, les manutentions, le transport Demisinusoïde Dents-de-scie à pointe finale Trapèze Robustesse de structure des montages Demisinusoïde Dents-de-scie à pointe finale Trapèze a Matériels terrestres à poste fixe ou seulement transportés par route, rail ou air, dans des emballages arrimés résistant aux chocs Matériels installés ou transportés arrimés dans des véhicules routiers ou ferroviaires normaux ou dans des avions de transport Composants en emballage arrimés transportés dans des véhicules à roues (routiers ou ferroviaires normaux), avions de transport subsoniques ou supersoniques, navires de commerce ou bateaux Composants montés dans des matériels transportés ou installés dans des véhicules à roues (routiers ou ferroviaires normaux), avions de transport subsoniques ou petits bateaux.