SAE-AIR-4964-2005-R2007.pdf
《SAE-AIR-4964-2005-R2007.pdf》由会员分享,可在线阅读,更多相关《SAE-AIR-4964-2005-R2007.pdf(7页珍藏版)》请在三一文库上搜索。
1、AEROSPACE INFORMATION REPORT AIR4964 Issued1998-03 Exposure Levels of UV Radiation in Nondestructive Inspection Processes INTRODUCTION The UV-A lamps (also known as blacklights) contain mercury-gas plasma that emit radiation specific to the mercury atomic transition spectrum. There are several discr
2、ete lines in the ultraviolet section of the electromagnetic spectrum (between 180 to 400 nm). The irradiance output is dependent on the gas pressure and the amount of mercury content. Higher values of these parameters result in significant increase in its UV emission. Blacklights used for NDT employ
3、 appropriate filters (integral or external to the light source) to minimize the visible light output (between 400 to 760 nm) vital to the fluorescent inspection processes. Furthermore, these filters also block any harmful radiation below 320 nm. Medical data suggests that radiation between 180 to 31
4、9 nm (UV-B and UV-C) can cause severe skin and eye burns. the sensitivity of the skin to such radiation is a function of the incident UV wavelength and its dosage. Normally, the erythemal effectiveness is strong between 180 to 300 nm, with rapid fall- off to 1% at 320 nm. Therefore, the filter chara
5、cteristics and the lamp head construction play an important role in the radiation safety and suitability of blacklights for the NDT industry. 1.SCOPE: Long wave ultraviolet or UV-A radiation (between 320 to 400 nm) is used for fluorescent inspections in magnetic particle and liquid penetrant examina
6、tions. The UV-A radiation is obtained from either fluorescent or high intensity discharge lamps that are stationary or portable. The commercially available UV-A lamps possess a large variation in intensity output that can cause a legitimate concern for possible health hazard. This draft reviews the
7、nature of UV-A radiation emitted by these lights, blacklight equipment, acceptable UV dosage limits adopted by the American Conference of Governmental Industrial Hygienists (ACGIH) and the European Standards Committee for Nondestructive Testing, and recommendation of proper practices when working wi
8、th UV-A radiation. 2.APPLICABLE DOCUMENTS: There are no referenced publications specified herein. SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its appli
9、cability and suitability for any particular use, including any patent infringement arising therefrom, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and
10、suggestions. Copyright 2007 SAE International All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO P
11、LACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: 724-776-4970 (outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org RATIONALE This document has been reaffirmed to comply with the SAE 5-year Review policy. Reaffirmed 2007-02 Copyright SA
12、E International Provided by IHS under license with SAELicensee=Defense Supply Ctr/5913977001 Not for Resale, 12/04/2007 19:47:10 MSTNo reproduction or networking permitted without license from IHS -,-,- SAE AIR4964 - 2 - 3.BLACKLIGHT EQUIPMENT: The most commonly used blacklights are low, medium, or
13、high-pressure mercury vapor discharge sources. The low pressure lamps are coated with special phosphor in order to maximize its UV-A output. The medium and high pressure lamps do not have phosphor coatings but operate at higher electrical power levels resulting in significantly higher UV-A output. T
14、ypically, the low pressure lamps are used in wash stations, whereas the medium or high pressure lamps are used in fluorescent inspection sites. Figures 1, 2, and 3 illustrate the emission profiles of such blacklights. A well- designed medium or high pressure blacklight should emit less than 0.25% an
15、d 1% of its total radiative output under 320 nm and above 400 nm, respectively. Spectroradiometric measurements conducted by the manufacturers of blacklight equipment must conform to the desirable emission characteristics. 4.UV-A AND VISIBLE LIGHT SPECIFICATIONS: The AMS, Military, ASTM and other in
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- SAE AIR 4964 2005 R2007
链接地址:https://www.31doc.com/p-3792693.html