Sensors and Actuators B Chemical, Journal Year: 2025, Volume and Issue: unknown, P. 137918 - 137918
Published: May 1, 2025
Language: Английский
Analytical Chemistry, Journal Year: 2025, Volume and Issue: unknown
Published: March 29, 2025
Carbon disulfide (CS2) and sulfur dioxide (SO2) are typical indicative gases for the early warning diagnosis of faults in gas-insulated switchgear. In this study, an optical sensing system is reported online detection CS2 SO2 based on a bidirectional self-correction technology (BSCT). First, differential absorption signals wavelength range 195-230 nm obtained using UV spectroscopy (UV-DOAS) technique. On basis, BSCT proposed to decouple spectral lines that exhibit significant overlap. This method primarily employs difference mutually correct spectra SO2, combined with reconstruction extract single-component from mixed gas spectra. Furthermore, effectiveness novel decoupling technique validated by comparing results standard at corresponding concentrations. Finally, quantitative relationships between concentrations target (CS2, SO2) parameters modeled least-squares method. The experimental show mean absolute percentage errors (19.00-3735.35 ppb) (0.19-38.77 ppm) 0.543 0.521%, respectively. At effective 50 cm, achieves lowest limits 0.5 ppb 12 representing best date ppb-ppm range.
Language: Английский
Citations
0
Microwave and Optical Technology Letters, Journal Year: 2025, Volume and Issue: 67(4)
Published: March 28, 2025
ABSTRACT Carbon dioxide (CO 2 ) is a major greenhouse gas contributing to climate change. Especially, the real‐time monitoring of its spatial and temporal variations have drawn significant attention in past few decades. In present work, we proposed Differential Absorption LiDAR (DIAL) system for CO concentration profiling. By employing dual‐wavelength 1.5 μm fiber laser an InGaAs/InP negative feedback avalanche diode (NFAD) based free‐running single‐photon detector (SPD), it allowed be compact, with low power consumptions. Comparisons between different pulse durations, energies peak powers were performed terms signal‐to‐noise ratio ( SNR backscattering signals LiDAR. It shown that three parameters combined effect on signal response behavior. After optimization energy, integration time, workflow profile retrieval, analytical performance has been evaluated. The evolution measured nicely coincides values from standard detector, correlation coefficient higher than 0.7 relative deviation within 6.8%. Subsequently, vertical observations carried out obtain height‐time plot concentrations, high spatial‐temporal resolution 25 m 15 min, respectively. results indicated diurnal variation at nearshore region. This compact DIAL shows promising potential streamlining online atmospheric over ocean buoy platforms.
Language: Английский
Citations
0
Analytical Chemistry, Journal Year: 2025, Volume and Issue: unknown
Published: March 31, 2025
The effects of H2O and SF6 on the relaxation rate CO molecules are studied using a fiber-optic photoacoustic sensor (FOPAS) that integrates resonant multipass cell with fiber cantilever. signal is enhanced by approximately 1 order magnitude under induction H2O. has high density compared to N2, which causes resonance frequency shift low frequency. responses CO/SF6 CO/N2 at tested without verify gas promoting effect process. impact increasing concentration manifests in three distinct stages, reflected gradual increase, sharp eventual saturation. corresponding ranges different stages 2000-12,000, 12,000-18,000, above 18,000 ppm, respectively. ratio precisely controlled, influence mechanism background mixture changes frequency, response, Q-factor studied. Furthermore, responsivity noise evaluated SF6. detection limits 10 ppb averaging times 100 400 s, makes this study applicable environment SF6, N2-SF6 mixtures as gas.
Language: Английский
Citations
0
Photoacoustics, Journal Year: 2025, Volume and Issue: 43, P. 100717 - 100717
Published: April 1, 2025
Language: Английский
Citations
0
Sensors and Actuators B Chemical, Journal Year: 2025, Volume and Issue: unknown, P. 137699 - 137699
Published: April 1, 2025
Language: Английский
Citations
0
Sensors and Actuators B Chemical, Journal Year: 2025, Volume and Issue: unknown, P. 137713 - 137713
Published: April 1, 2025
Language: Английский
Citations
0
Microwave and Optical Technology Letters, Journal Year: 2025, Volume and Issue: 67(4)
Published: April 1, 2025
ABSTRACT Due to the influence of automobile exhaust in underground parking lots all year round, a large amount carbon monoxide (CO) gas accumulates lots, endangering safety human lives. Based on tunable diode laser absorption spectroscopy (TDLAS) technology, CO detection system is designed be applied lots. A distributed feedback baser (DFB) was used scan peak at 1.566 μm, avoiding interference from other background gases. small multi‐pass cell (MPGC) with volume only 704 cm 3 and an effective optical range up 26 m. An improved wavelet thresholding denoising‐complete esemble empirical mode decomposition adaptive noise (IWTD‐CEEMDAN) denoising algorithm filter out effects noise, thereby improving signal‐to‐noise ratio (SNR) lowering limit system. greater cane rat algorithm‐bidirectional long short‐term memory (GCRA‐BiLSTM) concentration inversion improve accuracy inversion. According Allan variance, (LoD) sensor 11.57 ppm 1 s 0.124 117 s. series experiments are carried sensor, experimental results show that has good linearity, stability, LoD, which can realize real‐time monitoring garage CO, it important application value.
Language: Английский
Citations
0
Microwave and Optical Technology Letters, Journal Year: 2025, Volume and Issue: 67(5)
Published: April 27, 2025
ABSTRACT Accurate monitoring of atmospheric δ 13 C isotope is critical for quantifying anthropogenic carbon emissions and ecosystem responses within global cycle research. This study used off‐axis integrated cavity output spectroscopy (OA‐ICOS) combined with distributed feedback (DFB) laser achieved an effective absorption path length approximately 22 km, the simultaneous detection dioxide its (δ C) under background conditions. Laboratory validation demonstrated limits 104.5 ppb, 3.3 0.72‰ 12 CO 2 , C, respectively, a 2000 s integration time, alongside linear calibration R > 0.999. While Kalman filtering reduced concentration variability by 73.5%–74.7% improved precision 4.6 times. The sensor's capability to quantify isotopic ratios molecular concentrations in real‐time addresses gaps monitoring, offering robust tool climate research source–sink analysis, expanding applicability environmental sensing.
Language: Английский
Citations
0
Infrared Physics & Technology, Journal Year: 2025, Volume and Issue: unknown, P. 105894 - 105894
Published: April 1, 2025
Language: Английский
Citations
0
Applied Physics Letters, Journal Year: 2025, Volume and Issue: 126(17)
Published: April 28, 2025
A single fiber-optic photoacoustic sensor (FOPAS) is applied for the simultaneous detection of SF6 purity and decomposition derivative H2S, measurement results are corrected based on purity. H2S gas concentration identified by tracking frequency detecting signal 1f 2f, respectively. The influence resonance frequency, excitation intensity, cantilever response theoretically derived, simulated, experimentally verified. In range 80%–100%, there a linear relationship between purity, with 1.923 Hz/% minimum change limit 0.02%.The FOPAS designed T-type cell achieves 5 ppb normalized noise equivalent absorption coefficient reaches 4 × 10−10 cm−1 Hz−1/2 W. Taking 97% as an example, evaluated both before after correction. By correcting signal, accuracy improved 9%. adopting overall analysis method, high-precision high-sensitivity monitoring dual-state parameters has been achieved, providing technical support accurate early warning latent faults in gas-insulation equipment.
Language: Английский
Citations
0