Difference-frequency-based tunable absorption spectrometer for detection of atmospheric formaldehyde

Lancaster, D. G.; Fried, A.; Wert, B.; Henry, B.; Tittel, F. K.

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NASA NTRS · 20040088811

Difference-frequency-based tunable absorption spectrometer for detection of atmospheric formaldehyde

Lancaster, D. G.·Fried, A.·Wert, B.·Henry, B.·Tittel, F. K.

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Abstract

High-sensitivity detection of formaldehyde (CH2O) at 3.5315 micrometers (2831.64 cm-1) is reported with a diode-laser-pumped, fiber-coupled, periodically poled LiNbO3 spectroscopic source. This source replaced the Pb-salt diode laser Dewar assembly of an existing tunable diode-laser absorption spectrometer designed for ultrasensitive detection of CH2O. Spectra are recorded with 2f-modulation spectroscopy and zero-air rapid background subtraction. Initial measurements reported here, determined from multiple measurements of a flowing 7.7 parts per billion by volume (ppbv, parts in 10(9)) CH2O in air mixture, indicate replicate precisions as low as 0.24 ppbv.

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Non-NASA Center NASA Discipline Environmental Health Lasers Formaldehyde/analysis Spectrophotometry, Infrared/instrumentation Atmosphere/chemistry Environmental Monitoring/instrumentation Equipment Design Evaluation Studies Support, U.S. Gov't, Non-P.H.S Lead Support, Non-U.S. Gov't

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Lancaster, D. G., Fried, A., Wert, B., Henry, B., Tittel, F. K.. 2000-08-20. Difference-frequency-based tunable absorption spectrometer for detection of atmospheric formaldehyde. https://ntrs.nasa.gov/citations/20040088811

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