Hydrogen peroxide detection based on near-infrared TDLAS and Herriott cell

A compact open-path tunable diode laser absorption spectrometry (TDLAS) sensor has been developed for gas-phase hydrogen peroxide (H
2
O
2
) concentration monitoring during sterilization and aseptic disinfection. The sensor was based on a open-path multi-pass Herriott cell and wavelength modulated near-infrared diode laser. The sensor was calibrated by titrating the H
2
O
2
water which was obtained by exhausting measured gas-phase H2O2 through a water bubbler. A detection limit of 15 ppm with single measurement is achieved in the range of approximately 0–2000 ppm. The response time is 1s, mainly limited by ramping frequency and processing speed. It offers a combination of sensitivity, fast response, dynamic range, cost effectiveness and easy operation not available in alternative H
2
O
2
detectors.