The terms "contrast ratio", "opacity" and "hiding power" are used interchangeably throughout the coatings industry but on this page, in order to simplify matters, only the term opacity will be used. Opacity is defined as the ability of a coating to prevent the transmission of light. A practical example of this is the case where a yellow wall is painted using a red paint. The greater the opacity the red paint, the more efficient it will be at hiding the underlying yellow colour

        
        Opacity is defined by how a wet film of the test coating is applied to a black and white patterned substrate. After the film has dried, a reflectance meter or a spectrophotometer is used to measure the amount of light reflected from the overcoated black areas of the substrate. This is then expressed as a percentage of the amount of light reflected from the overcoated white areas. This value is the opacity of the film.

        
        A paint which is highly opaque will obscure the black and white areas to an equal extent. In this situation, equal amounts of light will be reflected from the overcoated black and white areas and consequently an opacity value of 100% will be obtained.

        NT 581 Reflectance meter is designed and manufactured according to international standard ISO2814, ISO 3906 , ISO 6504,BS 3900 and DIN 55984

Feature：

◆ Small and light, real easy to be carried and used.

◆ Auto zero calibration.

◆ One 1.5V alkaline Battery can be used for almost 60 hours and 10000 readings.

◆ Long-term stable light source needs no replacing.

Main Technical Parameters：
■ Measure range：0～100%

■ Measurement condition： 45°/ 0

■ Repeatability：1.5%

■ Power supply：One 1.5V alkaline Battery or rechargeable

■ Window Size：12×17mm（ellipse）

■ Dimension：114mm×32mm×64mm

■ Weight： 300g

■ Ordering Information：NT 581---Reflectance Meter