1. Introduction

A project log for Plant Foliage Health Monitor

Spectrophotometer To Determine Normalized Difference Vegetation Index (NDVI) Built With Raspberry Pi And NIR Spectral Sensor

guillermo-perez-guillenGuillermo Perez Guillen 05/30/2023 at 04:270 Comments


I assume you already have basic knowledge of optics. Optics is the study of light. Optics describes how light is created and how it travels. An important part of optics is the study of what happens when light hits different surfaces. When light hits a surface, it may be reflected, refracted, or absorbed.



Spectrophotometry is the quantitative measurement of the interaction of ultraviolet (UV), visible, and infrared (IR) radiation with a material and has an impact on a wide field of science and technology.  Spectrophotometry uses photometers, known as spectrophotometers, that can measure the intensity of a light beam at different wavelengths. 


Types of spectrophotometers:

A double-beam spectrophotometer compares the light intensity between two light paths, one path containing a reference sample and the other the test sample. A single-beam spectrophotometer measures the relative light intensity of the beam before and after a test sample is inserted. Although comparison measurements from double-beam instruments are easier and more stable, single-beam instruments can have a larger dynamic range and are optically simpler and more compact. Additionally, some specialized instruments, such as spectrophotometers built onto microscopes or telescopes, are single-beam instruments due to practicality.