1、Designation:E 2094 02Standard Practice forEvaluating the Service Life of Chromogenic Glazings1This standard is issued under the fixed designation E 2094;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A numb
2、er in parentheses indicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice is intended to provide guidance to archi-tects,specifiers,manufacturers,and other parties who have aninterest in evaluating the
3、service life of chromogenic glazings.1.2 This practice is intended to cover the main factors aboutservice life that must be considered when evaluating glazingsfor performance until the failure time is reached.However,users of this practice must be aware that other factors must beconsidered,such as t
4、he effect of the interaction of materials,theuse of the glazings,and to the environment in which achromogenic glazing is exposed over its service life.Users ofthis practice are specifically cautioned to be aware that failureof the plastic polyurethane thermal barrier in an aluminumwindow containing
5、a chromogenic blazing can cause a spread-ing or outward rotation of the glazing leges,called“hinging”or“clamming,”which reduces the edge pressure on an insulatedglazing(IG)unit,causing edge seal failure of the IG unit andallowing water to enter the IG unit and the glazing pocket.1.3 The test methods
6、 referenced herein are laboratory testsconducted under specified conditions.These test methods areintended to simulate and,in some cases,to also accelerateactual in-service use of the chromogenic glazings.Results fromthese test methods cannot be used to predict the performancewith time of units in t
7、he field unless actual corresponding fieldtests have been conducted and appropriate analyses have beenconducted to show performance can be predicted from accel-erated aging test methods.2.Referenced Documents2.1 ASTM Standards:C 168 Terminology Relating to Thermal Insulating Materi-als2E 632 Practic
8、e for Developing Accelerated Tests to AidPrediction of the Service Life of Building Components andMaterials3G 113 Terminology Relating to Natural and ArtificialWeathering Tests of Nonmetallic Materials33.Terminology3.1 DefinitionsRefer to the terminology given in Termi-nologies C 168 and G 113 and P
9、ractice E 632 for definitions ofgeneral terms.3.2 Definitions of Terms Specific to This Standard:3.2.1 accelerated aging testan aging test in which the rateof degradation of building components or materials is inten-tionally accelerated over that expected in actual service.3.2.2 chromogenic glazinga
10、 glazing consisting of one ormore layers of chromogenic materials,which are able to altertheir optical properties in response to a change in ambientconditions such as illumination intensity,temperature,appliedelectric field,and so forth.The changeable optical propertiesinclude transmittance,reflecta
11、nce,absorptance,and emittance.3.2.3 durabilitythe capability of maintaining the service-ability of a product,component,assembly,or construction overa specified time.3.2.4 serviceabilitythe capability of a building product,component,assembly,or construction to perform the func-tion(s)for which it was
12、 designed and constructed.3.2.5 service life(of a building component or material)the period of time after installation during which all propertiesexceed minimum acceptable values when routinely main-tained.4.Significance and Use4.1 This practice is important because producers of chro-mogenic glazing
13、s cannot wait for real-time in-service use toassess the product lifetime.Thus,a procedure is needed toestimate failure times based on accelerated weathering andrelated factors and tests.This practice does not provideguidance for how to follow the steps outlined as follows,but itprovides as much info
14、rmation as is practical in an ASTMpractice.5.Background5.1 Observations and measurements have shown that someof the performance characteristics of chromogenic glazingshave a tendency to deteriorate over time.In selecting materialsand glazings for any application,the ability of that glazing toperform
15、 over time is an indication of that glazings durability.The ability of the product to perform over time,at or better1This practice is under the jurisdiction of ASTM Committee E06 on Perfor-mance of Buildings and is the direct responsibility of Subcommittee E06.22 onDurability PerformanceCurrent edit
16、ion approved Oct.10,2002.Published November 2002.Originallypublished as E 209400.Last previous edition E 209400.2Annual Book of ASTM Standards,Vol 04.06.3Annual Book of ASTM Standards,Vol 14.04.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.than specified requirements,is an indication of the service lifeof the glazings.While these two indicators are related,thepurpose of this practice is to address the service life ofchromogenic glaz
