Method and device for measuring absolute concentration of singlet-state oxygen

Abstract

The invention provides a method and device for measuring the absolute concentration of singlet-state oxygen (O2(al(delta)). The device comprises a static pool, an infrared detection system and a data acquisition system, wherein the infrared detection system is composed of a chopper, a lens, a narrow-band interference optical filter, an infrared detector and a phase-locked amplifier. In the invention, by monitoring the infrared radiation attenuation change of O2(al(delta)) at 1.27 microns in the static pool and combining the dynamic model analysis in the static pool, the absolute response coefficient of the infrared detection system can be automatically calibrated, and the absolute concentration of O2(al(delta)) can be further measured in real time. Moreover, the infrared attenuation method of the static pool can be applied to the real-time measurement for any flowing system containing O2(al(delta)) by use of a 'flowing-stopping' technology.

Description

technical field [0001] The invention relates to a method for measuring singlet oxygen (O 2 (a 1 Δ)) The method of absolute concentration and the test device using this method. In particular, it relates to a method and a test device for measuring the absolute concentration of singlet oxygen by using an infrared radiation attenuation method. Background technique [0002] singlet oxygen O 2 (a 1 Δ) is the lowest electronically excited state of oxygen molecules, a long-lived metastable molecule, which plays a very important role in the photochemistry, photophysics and life processes in nature, and has received great attention for a long time. Moreover, it is also the direct energy source of the contemporary maximum power short-wavelength chemical laser - oxygen iodine chemical laser (COIL), its absolute concentration and yield (ie O 2 (a 1 Δ) and total O 2 Ratio) are two important parameters to evaluate the performance of the entire COIL system. In the past 30 years, man...

AI Technical Summary

Problems solved by technology

1) Spontaneous Raman spectroscopy, by comparing O in its Raman spectra 2 (a 1 Δ) and ground state oxygen O 2 (X) line intensity to determine O 2 (a 1 Δ) Yield (ie O 2 (a 1 Δ) to the concentration of total oxygen); it is not affected by window pollution and geometric configuration changes of the detection system, and is the current O 2 (a 1 Δ) The most accurate method for yield measurement; but in order to obtain O 2 (a 1 Δ) Absolute concentration requires adding a known flow of N 2 As a benchmark, this has an adverse effect on COIL performance

2) Absorption spectroscopy, including diode laser absorption spectroscopy, intracavity laser spectroscopy and optical cavity ring-down spectroscopy, using O 2 (X 3 ∑ g - →b 1 Σg + ) at the absorption transition near 762nm to directly measure the O 2 (X) Concentration, then according to the Cl measured by 325nm ultraviolet absorption method 2 O 2 (a 1 Δ) concentration, from which a large error is introduced

However, this method has historically required some other method (such as isothermal calorimetry) to pre-calibrate the response coefficient of the infrared detection system, so it is also vulnerable to factors such as window contamination and changes in the detection system geometry

[0004] The above-mentioned existing measurement methods and devices all have some shortcomings and deficiencies of one kind or another to varying degrees. Some methods require experimental devices to be more complicated and expensive, and some have large errors; while some require additional calibration of the detection system Response coefficient, and is susceptible to factors such as window contamination and changes in the geometry of the detection system

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