铂钴标准比色液 Pt-Co铂钴色度标准溶液 500黑曾

使用注意事项：使用前应恒温至20℃±4℃，并充分摇动以保证均匀。本标准物质打开后尽量一次性使用，使用过程中应严格防止沾污。

应用领域：水质色度

标准物质用途：色调接近Pt-Co色度的天然水、饮用水及浅色液体的色度测定标准、日常分析和检测、检测方法评价、仪器校准、实验室质量控制、认证考核现场专用标准物质。

用钾配成标准色列，与水样进行目视比色。每升水中含有1mg 铂和0.5mg 钴时所具有的颜色，称为1 度，作为标准色度单位。

如水样浑浊，则放置澄清，亦可用离心法或用孔径为0.45μm 滤膜过滤以去除悬浮物，但不能用滤纸过滤，因滤纸可吸附部分溶解于水的颜色。

APHA color, also referred to as the Hazen scale, and more appropriately as the Platinum Cobalt(Pt/Co) scale, is a color standard named for the American Public Health Association and defined by ASTM D1209. It was originally intended to describe the color of waste water, but its usage has expanded to include other industrial applications. APHA color is a color scale sometimes referred to as a "yellowness index" that is used to assess the quality of liquids that are clear to yellowish in color.

It is similar to the Hazen color test, to which it is sometimes incorrectly referred. The Hazen color test uses a Pt/Co solution and was developed for water treatment facilities where the Color of water could be used as a measure of concentration of dissolved and particulate material. Slight discoloration is measured in Hazen units (HU). Impurities can be deeply colored as well, for instance dissolved organic compounds called tannins can result in dark brown colors.

The scale for APHA color goes from 0 to 500 in units of parts per million of platinum cobalt to water. Zero on this scale represents distilled water, or what is more commonly called white water.

APHA standards can be used for both visual comparison and instrumental measurements. Standards can be bought pre-mixed or made by following guidelines prepared by the American Society for Testing and Materials' (ASTM). The mixture itself is an acidic solution of potassium hexachloro- platinate(IV) and cobalt(II) chloride with different levels of dilution for intermediate steps.