A miniaturized photometric ozone sensor using ultraviolet LED with unbalance differential correction and 3D printing

Ozone (O₃) sensing is of great significance to discern the ambient virulence from environmental deterioration. We developed a miniature, low power, low cost, and wide-temperature-range (-40 to +85 °C) photometric O₃ sensor for continuous and in-situ ambient O₃ monitoring. The primary innovation in this sensor is the combination of ultraviolet light emitting diodes (UV-LEDs) with unbalanced differential optical measurement with algorithm correction, sensitive electronic module, and 3D printing fabrication. The sensor operated in the Hartley band of O₃ with a UV-LED (258 nm, 1mw) and software phase-sensitive detection. Experimental results showed high performance of the sensor with detection limit of 8 ppb and relative error of 0.22%. The dimension, power, and weight of the sensor are as low as 11.4 × 5 × 2.4 cm, 0.5 W, and 0.1 kg, respectively, much lower than that of most O₃ sensors. We also demonstrated the feasibility of the sensor in continuously O₃ monitoring in an office.