This application note describes the steps involved in measuring the cover and shade protection factors of synthetic shadecloth. The method is based on measuring the absorption of UVR by the shadecloth samples using a spectrophotometric method, from which the shade protection factor is determined.
The document outlines a spectrophotometric method to assess ultraviolet radiation (UVR) protection provided by synthetic shadecloth. It details how to determine cover and shade factors, which are critical for horticultural and architectural applications where plants or humans require specific levels of sun exposure.
The guide provides step-by-step instructions for using the Cary 1/3E UV-Vis Spectrophotometer with a Labsphere DRA-CA-30 Diffuse Reflectance Accessory. It explains how to calculate cover factors based on transmission at 350 nm and shade factors over the range of 290 to 770 nm, including specific calculations for UVR blockage and Photosynthetically Active Radiation (PAR) transmission.
The cover factor is calculated using the formula: Cover factor = 100 - %Tav, where %Tav is the average of readings at 350 nm.
The required equipment includes a Cary 1/3E UV-Vis Spectrophotometer, Labsphere DRA-CA-30 Diffuse Reflectance Accessory, Schott UG 11 filter, and Shadecloth Easy Menu software.
The shade factor is calculated using the formula: Shade Factor = 100 - %Tav, where %Tav is the average of readings over the wavelength range 290 to 770 nm.