Jinsi ya kutumia nyuzinyuzi za umeme kupima kanuni ya halijoto-INNO

Principle of Fluorescence Lifetime Temperature Measurement

After being irradiated with light, the electrons in the sensitive material absorb photons and transition from low energy level to excited state high energy level, and then return to low energy level through radiation transition, kutoa fluorescence. The sustained fluorescence emission after the excitation light is eliminated depends on the lifetime of the excited state. This emission typically decays exponentially, and the time constant of exponential decay can be used to measure the lifetime of the excited state, which is called the fluorescence lifetime or fluorescence decay time.

Fluorescence lifetime temperature sensor

The length of fluorescence lifetime depends on the temperature. Fluorescence lifetime temperature sensors emit linear spectra in the visible spectrum after certain rare earth fluorescent substances are irradiated and excited by ultraviolet light, Hiyo ni, fluorescence and its afterglow are the luminescence after the excitation stops. If a parameter of fluorescence is modulated by temperature and the relationship is monotonic, this relationship can be used for temperature measurement. The intensity of the linear spectrum is related to the intensity of the excitation light source and the temperature of the fluorescent material. If the light source is constant, the intensity of the fluorescent linear spectrum is a single value function of temperature and decays over time. Ujumla, the lower the external temperature, the stronger the fluorescence and the slower the decay of afterglow. By filtering out the excitation spectrum through a filter and measuring the intensity of the fluorescence afterglow emission spectral lines, the temperature can be determined. But this measurement method requires stable excitation light intensity and signal channel, which is difficult to achieve, so it is rarely used. Zaidi ya hayo, the decay time constant of fluorescence afterglow is also a single value function of temperature.

From the perspective of semiconductor theory, the decay and disappearance of afterglow is the quenching process of light. joto la juu, the stronger the lattice vibration, the more phonons participate in absorption, and the faster the light quenching. Basi, the temperature of fluorescent materials determines the speed of light quenching, Hiyo ni, the size of the decay time constant.

Faida kubwa ya kutumia maisha ya fluorescence kwa kipimo cha joto ni kwamba uhusiano wa ubadilishaji wa joto huamuliwa na maisha ya fluorescence., na haiathiriwi na mambo mengine ya nje kama vile mabadiliko ya msisimko wa chanzo cha mwanga, ufanisi wa maambukizi ya nyuzi, au shahada ya kuunganisha. Basi, ina manufaa makubwa zaidi ya mbinu ya kipimo cha halijoto kwa kutumia kiwango cha juu cha umeme au uwiano wa kiwango kama ishara ya kutambua halijoto., na inategemea kanuni ya kipimo cha joto la fiber optic.