基礎(chǔ)防雷外文資料翻譯-資料下載頁(yè)
【導(dǎo)讀】閃電是一個(gè)反復(fù)無(wú)常，隨機(jī)和不可預(yù)測(cè)的事件。過(guò)400kA；溫度超過(guò)50000華氏度，速度接近或超過(guò)三分之一的光速。以來(lái)持續(xù)雷擊地球約100次每秒。美國(guó)保險(xiǎn)公司的資料顯示每57索賠有一次是因。這些數(shù)據(jù)還不包括商業(yè)，政府和工業(yè)雷電造成的損失。雷電造成的火災(zāi)超過(guò)26000起，財(cái)產(chǎn)損失在5-6億美元。從頂層雷云朝地球的向下脈沖，尋求電氣地面目標(biāo)。地基對(duì)象對(duì)此事件發(fā)出不同程度。一個(gè)“聚集區(qū)”加劇當(dāng)?shù)氐碾妶?chǎng)。直接影響是有電阻發(fā)熱，出現(xiàn)電弧并可能。間接影響是，多數(shù)時(shí)候?qū)﹄娙?，電感出現(xiàn)電磁影響。風(fēng)險(xiǎn)緩解辦法來(lái)實(shí)現(xiàn)保護(hù)。從富蘭克林研究雷電開(kāi)始，就使用避雷針進(jìn)行建筑物防雷并引流接地。型的避雷針來(lái)達(dá)到設(shè)計(jì)要求。是一種有效的避雷針類型。高空防雷裝置的設(shè)計(jì)和性能是一個(gè)有爭(zhēng)議的并尚未解決。進(jìn)一步的研究和試驗(yàn)仍在進(jìn)行。漸進(jìn)彎曲半徑最小為八英寸，應(yīng)采取避免閃絡(luò)的方式。是將雷電脈沖傳入大地來(lái)減少危害的。2020年空氣污染指數(shù)，對(duì)所產(chǎn)生的靜電，火災(zāi)2020閃電和雜散電流，美國(guó)石
【正文】 all metal objects, crouching with feet together, head bowed, and placing hands on ears to reduce acoustic shock. Measuring lightning39。s distance is easy. Use the Flash/Bang (F/B) technique. For every count of five from the time of seeing the lightning stroke to hearing the associated thunder, lightning is one mile away. A F/B of 10 = 2 miles。 a F/B of 20 = 4 miles, etc. Since the distance from Strike A to Strike B to Strike C can be as much as 58 miles. Be conservative and suspend activities when you first hear thunder, if possible. Do not resume outdoor activities until 20 minutes has past from the last observable thunder or lightning. Organizations should adopt a Lightning Safety Policy and integrate it into their overall safety plan. Testing Modern diagnostic testing is available to mimic the performance of lightning conducting devices as well as to indicate the general route of lightning through structures. This testing typically is low power, 50 watt or less. It is traceable, but will not trip MOVs, gas tube arrestors, or other transient protection devices. Knowing the behavior of an event prior to occurrence is every businessman39。s earnest hope. With such techniques, lightning paths can be forecast reliably. Codes amp。 Standards The marketplace abounds with exaggerated claims of product perfection. Frequently referenced codes and installation standards are inplete, out dated and promulgated by mercial interests. On the other hand IEC, IEEE, MILSTD, FAA, NASA and similar documents are supported by background engineering, the peerreview process, and are technical in nature. Summary It is important that all of the above subjects be considered in a lightning safety analysis. There is no Utopia in lightning protection. Lightning may ignore every defense man can conceive. A systematic hazard mitigation approach to lightning safety is a prudent course of action. References 1. API 2020, Protection Against Ignitions Arising out of Static, Lightning, and Stray Currents, American Petroleum Institute, Washington DC, December 1991. 2. Golde, ., Lightning, Academic Press, NY, 1977. 3. Hasse, P., Overvoltage Protection of Low Voltage Systems, Peter Peregrinus Press, London, 1992. 4. Hovath, Tibor, Computation of Lightning Protection, John Wiley, NY, 1991. 5. IEEE Std 1100, Powering and Grounding of Sensitive Electronic Equipment, IEEE, NY, NY. 1992. 6. KSCSTDE0012B, Standard for Bonding and Grounding, Engineering Development Directorate, John F. Kennedy Space Center, NASA, 1991. 7. Morris, ., ., RocketTriggered Lightning Studies for the Protection of Critical Assets, IEEE Transactions on Industry Applications, Vol. 30, No. 3, May/June 1994. 8. Sunde, . Earth Conduction Effects in Transmission Systems, D. Van Nostrand Co., NY, 1949. 9. Towne, D., Wave Phenomena, Dover Publications, NY. 10. Uman, Martin, Lightning, Dover Publications, NY, 1984.
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