Optics Laboratory

★ Light Source Measurement ★
Different light sources have different wavelength properties. With a spectrometer, we can measure the wavelength properties of a light source. For example, measuring LED lights of different colors results in different spectral distribution graphs. If we measure a red LED light, we would get a spectral distribution graph like the following, since its wavelength range falls within 620-740 nm.


● Applicable areas
Light inspection for LED industries, colorimetry inspection for FPD industries, fluorescence, Raman, laser, controlling the color of the exposure light, etc.

Transmittance can be derived from measuring absorbance.

Defining Transmittance
Transmittance is defined as: T = (exit light / incident light) x 100%. This formula is used to determine the transmittance of a test object at a certain wavelength range.

Measuring UV Protection of Sunglasses
Sunglasses testing standard CNS15067, for example, focuses on two wavelength ranges in its certification: 280-315 nm and 315-350 nm.

● Applicable areas

Monitoring suspended solids in water, COD monitoring, turbidity monitoring, etc.

  
 
★ Reflectance Measurement ★

If we put the test object and a total reflection object under the same light source, and then compare the amounts of radiation reflected from them, we can get the reflectance of the test object, as defined in the following formula:
Rλ = (φλ)/(φDλ)
φλ is the radiation from the test object
φDλ is the radiation from the total reflection object
The color of a test object can be defined by its reflectance spectrum, because objects of different colors have different reflectance spectrum.

● Applicable areas
Color matching, mixing, and verification for textile, printing, dyeing, electroplating, paint-coating industries, etc.
  

 
★ Absorbance Measurement ★

One other basic measurement offered by spectrometers is absorbance. Normally, users would measure the absorbance of a mixed solution to determine its concentration, because the higher the concentration, the greater the absorbance. This method calculates how much light the solution absorbs at a particular wavelength to determine its absorbance.

Beer-Lambert law relates the optical attenuation of a physical material containing a single attenuating species of uniform concentration to the optical path length through the sample and absorptivity of the species. This expression is:

Where

  is the molar attenuation coefficient or absorptivity of the attenuating species
  is the optical path length
  is the concentration of the attenuating species

 

Home health care devices, preventive medicine and personal health management, animal examination devices, etc.
 

 
★ Measuring a halogen lamp to observe its spectral distribution ★
●Purpose：Demonstrating how spectrometers can be used to measure a light-emitting object through the direct measurement of a halogen lamp.
●Items required：Spectrometer, USB cable, short fiber optic cable, halogen lamp, measurement platform.
●Measurement setup：Please set up the measurement environment as shown in the figure as shown below.

● Purpose： The higher the concentration, the greater the absorbance. This method calculates how much light the solution absorbs at a particular wavelength to determine its absorbance.
● Items required：Spectrometer, USB cable, short fiber optic cable, halogen lamp, measurement platform, cuvette holder, square cuvette, water, and red ink.
● Measurement setup：Please set up the measurement environment as shown in the figure as shown below. 

★ Measuring colored laminated glasses to observe their transmittance ★

●Purpose：
(1) Transmittance is defined as: T = (exit light / incident light) x 100%. This formula is used to determine the transmittance of a test object at a certain wavelength range.
(2) Laminated glasses of different colors allow light of different wavelengths to pass through, as the following table shows: