Single Beam spectrophotometer

A single beam spectrophotometer is an analytical instrument used to measure the absorbance or transmittance of light by a sample at specific wavelengths. It operates on the principle that different substances absorb light of specific wavelengths in characteristic ways, allowing qualitative and quantitative analysis. In this instrument, a single beam of light passes through the sample, and the intensity of light before and after the sample is compared. The difference in light intensity gives the absorbance, which is related to the concentration of the analyte according to Beer–Lambert’s law.

Key Components:

• Light source: Provides a continuous spectrum of radiation (commonly tungsten, deuterium, or LED lamps).
• Monochromator (prism or diffraction grating): Isolates a specific wavelength of light.
• Sample holder (cuvette): Holds the liquid or solid sample for analysis.
• Detector (photodiode/photomultiplier): Measures transmitted light intensity.
• Readout/display system: Shows absorbance or transmittance values.