Algorithms used for Microspectroscopy

Microscope spectrometers are used in many fields.

Light is transmitted through the sample, collected by the objective and focused onto the aperture and simulaneously an image and spectrum are collected.

Transmission spectrum from a microspectrophotometer.

Transmittance
Transmittance calculates a transmission spectrum from a sample and reference single-beam spectra.

From Two Single-Beam Spectra a transmission spectrum using the following formula:

Percent transmission calculation

where R is the single beam spectrum of the reference material, S is the single beam spectrum of the sample and D is the dark counts of the system.

From Absorbance Data a transmission spectrum can be generated using the following formula:

Convert absorbance to percent transmission.

where A is the absorbance value. This is a calculation from data that has already been collected.

 

Absorbance
Absorbance calculates an absorption spectrum from a sample and reference single-beam spectra or from a transmission spectrum.

From Two Single-Beam Spectra an absorption spectrum can be generated using the following formula:

Absorbance calculation

where R is the single beam spectrum of the reference material, S is the single beam spectrum of the sample and D is the dark counts of the system.

From Transmission Data an absorption spectrum can be generated using the following formula:

Convert percent transmission to absorance.

where %T is the percent transmittance value. This is a calculation from data that has already been collected.

 

Reflectance
Reflectance calculates a reflectance spectrum from a sample and reference single-beam spectra or from an log 1/R spectrum.

From Two Single-Beam Spectra a reflectance spectrum can be generated using the following formula:

Percent reflectance calculation.

where R is the single beam spectrum of the reference material, S is the single beam spectrum of the sample and D is the dark counts of the system.