Formaldehyde sensor design: Integrating fiber bundle and concave mirror techniques

This study successfully demonstrates the detection of formaldehyde concentration using a fiber bundle with a concave mirror as a reflector. The setup employs an Optical Stimulated Luminescence (OSL) light source connected to the fiber bundle. Light transmitted through the fiber interacts with the formaldehyde solution sample, reflects off the concave mirror, and is received by the collecting fiber before being analyzed by a spectrometer. The experimental results indicate that the detected light intensity decreases linearly with increasing formaldehyde concentration, without any wavelength shift. This suggests that while the absorption properties of formaldehyde remain constant, the quantity of absorbed light increases proportionally with concentration. The sensor design exhibits excellent sensitivity, linearity, and stability, achieving a sensitivity range of 0%–6% at 5004.62 counts/% with a linearity of 97% and a resolution of 0.037%.