What is "fluorometer"

n. An instrument used to detect and measure fluorescence.

A fluorometer or fluorimeter is a device used to measure parameters of fluorescence: its intensity and wavelength distribution of emission spectrum after excitation by a certain spectrum of light. These parameters are used to identify the presence and the amount of specific molecules in a medium. Modern fluorometers are capable of detecting fluorescent molecule concentrations as low as 1 part per trillion.

Fluorescence analysis can be orders of magnitude more sensitive than other techniques. Applications include chemistry/ biochemistry, medicine, environmental monitoring. For instance, they are used to measure chlorophyll fluorescence to investigate plant physiology.