1. What is the Beer-Lambert Law?

Definition: The Beer-Lambert law relates the attenuation of light to the properties of the material through which the light is traveling.

Purpose: It helps in determining the concentration of solutions or the absorbance of materials based on light intensity measurements.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( A \) — Absorbance (unitless)
• \( I_i \) — Intensity of incident radiation (W/m²·sr)
• \( I_t \) — Intensity of transmitted radiation (W/m²·sr)

Explanation: The logarithm of the ratio of incident to transmitted light intensity gives the absorbance of the material.

3. Importance of Absorbance Calculation

Details: Absorbance measurements are crucial in spectroscopy, chemical analysis, and determining concentrations of solutions.

4. Using the Calculator

Tips: Enter the incident radiation intensity and transmitted radiation intensity (must be ≤ incident intensity). Both values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What does absorbance tell us?
A: Absorbance indicates how much light is absorbed by a sample at a particular wavelength.

Q2: What units are used for radiation intensity?
A: Typically watts per square meter per steradian (W/m²·sr), but the calculator works with any consistent units.

Q3: Why use log10 instead of natural logarithm?
A: By convention, absorbance uses base-10 logarithms (common logs) in spectroscopy.

Q4: What if transmitted intensity is greater than incident?
A: This is physically impossible in normal conditions and will return an error.

Q5: How is this related to solution concentration?
A: The full Beer-Lambert law includes concentration: A = εlc, where ε is molar absorptivity and l is path length.