Optical Density Calculator:
Enter the values of incident optical intensity, I and transmitted optical intensity, I to determine the value of Optical density, OD.
Optical Density Formula:
Optical density (OD) is a measure of how much a material can absorb light. It is a logarithmic measurement that quantifies the attenuation of light as it passes through a substance.
Optical density is commonly used in fields like chemistry, biology, and optics to assess the concentration of solutions or the transparency of materials.
Higher optical density indicates greater absorption and less transmission of light through the material.
Incident light intensity – the initial intensity of light entering the material.
Transmitted light intensity – the intensity of light that passes through the material.
The higher the difference between incoming (Io) and transmitted (I) light intensity, the more light is absorbed. This translates to a higher OD value.
The formula uses a logarithm (log) function because the relationship between light intensity and OD is not linear. Small changes in transmitted light (I) can result in significant changes in OD.
Optical density, OD is calculated by taking the log of the incident optical intensity, I divide by the transmitted optical intensity, I.
Optical density, OD = log10 (I / I)
OD = optical density.
I = incident optical density.
I = transmitted optical intensity.
Optical Density Calculation:
- A sample allows 10% of the incident light to pass through. Calculate its optical density.
Given: I = 100, I = 10.
Optical density, OD = log10 (I / I)
OD = log10 (100 / 10)
OD = log10 (10)
OD = 1.
- A solution has an optical density of 2. If the intensity of the incident light is 200 units, calculate the intensity of the transmitted light.
Given: I = 200, OD = 2.
Optical density, OD = log10 (I / I)
10OD = I / I
I = I / 10OD
I = 200 / 102
I = 200 / 100
I = 2.