With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: In 2015, Harry Styles released an album.
text_B: 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 .. fluorescence. fluorescence. wavelength. wavelength. emission spectrum. emission spectrum. excitation. Excitation spectrum. 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 .. chemistry. chemistry. biochemistry. biochemistry. medicine. medicine. environmental. Environmental quality. For instance , they are used to measure chlorophyll fluorescence to investigate plant physiology .. fluorescence. fluorescence. chlorophyll fluorescence. chlorophyll fluorescence. plant. plant
not_related.