A spectrophotometer is an instrument that measures the amount of photons (the intensity of light) absorbed after it passes through sample solution. With the spectrophotometer, the amount of a known chemical substance (concentrations) can also be determined by measuring the intensity of light detected.
The spectrophotometer measures the amount of visible light absorbed by a solution. To obtain a reading, the spectrophotometer will direct a known amount of light through a cuvette filled with solution and will measure the amount of light that passes through the cuvette.

A spectrophotometer is an instrument that measures the amount of photons (the intensity of light) absorbed after it passes through sample solution. With the spectrophotometer, the amount of a known chemical substance (concentrations) can also be determined by measuring the intensity of light detected.
The spectrophotometer measures the amount of visible light absorbed by a solution. To obtain a reading, the spectrophotometer will direct a known amount of light through a cuvette filled with solution and will measure the amount of light that passes through the cuvette.