regul eec commiss march classif good head subhead no common custom tariff commiss european commun regard treati establish european econom commun regard council regul eec januari measur ensur uniform applic common custom tariff articl thereof provis made ensur uniform applic common custom tariff view classif quot vitreou china quot quot semi vitreou china quot product ceram product vitrifi greater lesser extent slightli greyish white artifici colour ceram materi smooth tongu common custom tariff annex council regul eec june amend council regul eec decemb compris head subhead no product porcelain head subhead no product ceram materi purpos classif common custom tariff quot vitreou china quot quot semi vitreou china quot product aforesaid regard special properti porcelain poros densiti transluc quot vitreou china quot quot semi vitreou china quot product classifi head subhead no simultan inter alia properti poros exceed densiti transluc ceram materi approxim mm thick colour bodi coat colour opaqu varnish enamel desir prescrib method analysi poros transluc product question assess uniformli measur provid regul accord opinion committe common custom tariff nomenclatur adopt regul articl quot vitreou china quot quot semi vitreou china quot ceram product vitrifi greater lesser extent slightli greyish white artifici colour ceram materi smooth tongu classifi head subhead no common custom tariff simultan properti degre poros effici water absorpt exceed measur method set annex densiti transluc thick approxim mm measur method set annex ii oj oj oj criterion appli ceram materi colour bodi coat colour opaqu varnish enamel articl regul enter forc eighth dai public offici journal european commun regul bind entireti directli applic member state brussel march commiss presid mansholt annex determin coeffici water absorpt object definit object test determin coeffici water absorpt ceram materi coeffici repres percentag calcul relat initi weight ceram materi prepar test piec carri test minimum test piec item test enamel part articl enamel surfac surfac area test piec squar centimetr maximum thick millimetr includ enamel dry test piec kiln ºc hour cool dryer determin weight wd nearest gramm immedi immers test piec distil water touch bottom contain boil water hour leav test piec water hour remov wipe surfac water clean slightli damp cloth dry caviti hole slightli damp thin brush ascertain quot wet quot weight ww coeffici water absorpt test piec obtain multipli increas weight divid dry weight gt pic file quot quot gt evalu result averag coeffici water absorpt test piec express percentag water absorpt coeffici ceram materi annex ii transluc test definit outlin object visibl test piec millimetr thick dark room centimetr lamp enclos box emit beam light lumen lamp chang hour test apparatu sketch annex apparatu consist box paint intern white mat finish end lamp hole made opposit end outlin object test piec dimens box length length lamp centimetr width height approxim centimetr diamet hole approxim centimetr gt pic file quot quot gt