Enter the percent transmittance into the calculator to determine the absorbance. This calculator helps in converting transmittance values into absorbance, which is useful in various scientific and engineering fields, particularly in spectrophotometry.
Percent Transmittance to Absorbance Formula
The following formula is used to convert percent transmittance to absorbance:
A = -log10(T / 100)
Variables:
- A is the absorbance (unitless)
- T is the percent transmittance (%)
To convert percent transmittance to absorbance, take the negative logarithm (base 10) of the transmittance divided by 100.
What is Absorbance?
Absorbance is a measure of the amount of light absorbed by a sample. It is a dimensionless quantity used in spectrophotometry to quantify the concentration of solutes in solution. Absorbance is related to transmittance, which is the fraction of light that passes through a sample. In many scientific applications, absorbance is preferred over percent transmittance because it is directly proportional to the concentration of the absorbing species according to Beer-Lambert law.
How to Calculate Absorbance from Percent Transmittance?
The following steps outline how to calculate the absorbance from percent transmittance:
- First, determine the percent transmittance (T) of the sample.
- Next, use the formula A = -log10(T / 100) to calculate the absorbance (A).
- Finally, enter the percent transmittance into the calculator above to verify the absorbance value.
Example Problem:
Use the following variable as an example problem to test your knowledge.
Percent Transmittance (T) = 35%
Using the formula, the absorbance (A) is calculated as:
A = -log10(35 / 100) = 0.4559
