In a way that uses a spectrophotometer to measure how much light something absorbs or lets through.
This word is used in science and is very technical.
Examples:
She measured the liquid spectrophotometrically.
The scientist studied the substance spectrophotometrically.
Spectrophotometrically, the results were very clear.
He tried to cook spectrophotometrically, but it didn't work.
They could see spectrophotometrically how much light the liquid took in.
The machine worked spectrophotometrically and showed the right results.