{"id":617416,"date":"2024-11-05T23:24:41","date_gmt":"2024-11-05T23:24:41","guid":{"rendered":"https:\/\/pdfstandards.shop\/product\/uncategorized\/iso-4891999\/"},"modified":"2024-11-05T23:24:41","modified_gmt":"2024-11-05T23:24:41","slug":"iso-4891999","status":"publish","type":"product","link":"https:\/\/pdfstandards.shop\/product\/publishers\/iso\/iso-4891999\/","title":{"rendered":"ISO 489:1999"},"content":{"rendered":"<p>This International Standard specifies two test methods for determining the refractive index of plastics, namely:<\/p>\n<p>  Method A: a refractometric method for measuring the refractive index of moulded parts, cast or extruded sheet<\/p>\n<p>or film, by means of a refractometer. It is applicable not only to isotropic transparent, translucent, coloured or<\/p>\n<p>opaque materials but also to anisotropic materials. The method is recommended when great accuracy is<\/p>\n<p>required. It is not applicable to powdered or granulated material.<\/p>\n<p>  Method B: an immersion method (making use of the Becke line phenomenon) for determining the refractive<\/p>\n<p>index of powdered or granulated transparent materials by means of a microscope. Monochromatic light should,<\/p>\n<p>in general, be used to avoid dispersion effects. The accuracy of this method is about the same as that of<\/p>\n<p>method A. It is applicable to isotropic translucent, coloured materials but is not applicable to opaque materials<\/p>\n<p>nor to anisotropic materials.<\/p>\n<p>NOTE 1 The refractive index is a fundamental property which can be used for checking purity and composition, for the<\/p>\n<p>identification of materials and for the design of optical parts. The change in refractive index with temperature may give an<\/p>\n<p>indication of transition points of materials.<\/p>\n<p>NOTE 2 The accuracy of method B is approximately the same as that of method A when an experienced operator uses the<\/p>\n<p>method with extreme care (see clause 7).<\/p>\n","protected":false},"excerpt":{"rendered":"<p><b>Plastics \u2014 Determination of refractive index<\/b><\/p>\n<table style=\"width: 100%\" border=\"0\" cellspacing=\"0\" cellpadding=\"0\">\n<tbody>\n<tr>\n<td>Published By<\/td>\n<td>Publication Date<\/td>\n<td>Number of Pages<\/td>\n<\/tr>\n<tr>\n<td><a href=\"https:\/\/pdfstandards.shop\/product-category\/publishers\/iso\/\"><b>ISO<\/b><\/a><\/td>\n<td>1999-04<\/td>\n<td>16<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"featured_media":617427,"template":"","meta":{"rank_math_lock_modified_date":false,"ep_exclude_from_search":false},"product_cat":[1177,2634],"product_tag":[],"class_list":{"0":"post-617416","1":"product","2":"type-product","3":"status-publish","4":"has-post-thumbnail","6":"product_cat-83-080-01","7":"product_cat-iso","9":"first","10":"instock","11":"sold-individually","12":"shipping-taxable","13":"purchasable","14":"product-type-simple"},"_links":{"self":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product\/617416","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/types\/product"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media\/617427"}],"wp:attachment":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media?parent=617416"}],"wp:term":[{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_cat?post=617416"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_tag?post=617416"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}