Working principle of optical oxygen sensors

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Optical oxygen (O2) sensors can quickly and reliably detect the O2 content in liquid or gas media. Generally, O2 measurement is not affected by other gases. An optical oxygen sensor includes: a light-emitting diode (LED), an inert carrier that holds the photosensitive layer, in which dye molecules are embedded in a polymer matrix and protected by an optically insulating layer, as well as a photodiode along with a filter to quantify the light emitted. What happens under hypoxic or anoxic conditions? If there is no O2 in the sample, the dye absorbs the excitation light emitted by the LED, transfers it to a higher energy level, and emits light again. The emission light has a delay, and the wavelengths differ. The filter in front of the photodiode ensures that only the emitted light is detected. If oxygen is present in the sample, the dye will absorb the excitation light, but in the excited state, the energy is absorbed by oxygen molecules. The dye now has even less emitted energy left. The more oxygen there is, the less light reaches the photodiode. The characteristics of the sensor illustrate this: No consumption: no oxygen is used during measurement; User-friendly: no electrolyte is required, and there is no need for polarization time; Environmentally friendly: no chemicals are needed. How is oxygen concentration quantified? Delay time of the emitted light relative to the excitation light. The time delay between the excitation light and the emission light is independent of intensity. It is proportional to the partial pressure of O2; knowing the atmospheric pressure, it can be used to measure the O2 concentration. Fluorescent oxygen sensor LOX-02
I. Applications
1. Ventilators
2. Laboratory equipment
3. Agriculture
4. Detection of exhaust gases from boilers
5. Purging, medical applications
6. Incubation equipment, incubators
7. Portable devices for oxygen detection
II. Features
·1. Optical technology based on fluorescence; non-electrochemical
2. Contains no harmful substances ； Complies with RoHS and REACH 3; connects directly to the microcontroller without any additional circuits; pre-calibrated at the factory; high precision and fast response time; maintenance-free; long service life of over 5 years. III. Technical specifications: Voltage (Vs): 4.5 – 5.5V; Supply current (Is)