The core working principle of PID sensor is to ionize volatile organic compounds (VOCs) by ultraviolet light, and convert the gas concentration by detecting the current generated by ionization.

Core working logic

Ultraviolet excitation: the ultraviolet lamp in the sensor emits photons with specific energy and irradiates the gas to be detected.

Gas ionization: When the photon energy is greater than the ionization energy of VOCs, the molecular bond is broken, resulting in positive ions and free electrons.

Current detection: Ions generated by ionization move directionally under the action of electric field, forming a weak current, and the current intensity is positively correlated with VOCs concentration.

Signal conversion: through circuit amplification and signal processing, the current signal is converted into readable gas concentration value.

Key feature supplement

It only responds to ionizable VOCs, but does not respond to inert gases such as nitrogen and oxygen.

The energy of ultraviolet lamp (such as 10.6eV and 11.7eV) determines the range of detectable VOCs.

It has high detection accuracy, can identify VOCs with low concentration (ppb level) and has fast response speed.