How does a spectrophotometer work?
2 min read
2 hours ago
Published on Oct 11, 2025
This response is partially generated with the help of AI. It may contain inaccuracies.
Table of Contents
Introduction
This tutorial explains how a spectrophotometer works, a crucial instrument in laboratories for analyzing the absorbance and transmittance of light through a sample. Understanding its operation is key for anyone working in fields like biology, chemistry, or environmental science.
Step 1: Understanding the Light Source
- A lamp serves as the light source for the spectrophotometer.
- The lamp emits a beam of light that is directed towards the diffraction grating.
Step 2: The Role of the Diffraction Grating
- The diffraction grating acts like a prism, separating the light into its component wavelengths.
- As it rotates, the grating ensures that only a specific wavelength of light is directed toward the exit slit.
Step 3: Interaction with the Sample
- The selected wavelength of light interacts with the sample placed in the path of the beam.
- This interaction is crucial as it determines how much light will pass through or be absorbed by the sample.
Step 4: Measuring Transmittance and Absorbance
- After the light passes through the sample, it reaches the detector.
- Transmittance measures the amount of light that passes completely through the sample and strikes the detector.
- Absorbance quantifies the amount of light that is absorbed by the sample.
Step 5: Data Conversion and Display
- The detector senses the transmitted light and converts this information into a digital signal.
- This signal is displayed on a digital screen, providing a clear measurement of absorbance and transmittance for analysis.
Conclusion
A spectrophotometer is a vital tool for measuring how samples interact with light. By understanding its components and processes, you can effectively use this instrument in various scientific applications. For hands-on practice, consider using a virtual spectrophotometer available at NC BioNetwork.