Articles | Volume 10, issue 3
Atmos. Meas. Tech., 10, 1203–1213, 2017
https://doi.org/10.5194/amt-10-1203-2017
Atmos. Meas. Tech., 10, 1203–1213, 2017
https://doi.org/10.5194/amt-10-1203-2017

Research article 29 Mar 2017

Research article | 29 Mar 2017

Calibration of a multi-pass photoacoustic spectrometer cell using light-absorbing aerosols

Nir Bluvshtein1, J. Michel Flores1, Quanfu He1, Enrico Segre2, Lior Segev1, Nina Hong3, Andrea Donohue3, James N. Hilfiker3, and Yinon Rudich1 Nir Bluvshtein et al.
  • 1Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot 76100, Israel
  • 2Physical services, Weizmann Institute of Science, Rehovot 76100, Israel
  • 3J.A. Woollam Co., Inc., 645 M Street, Suite 102 Lincoln, NE 68508, USA

Abstract. The multi-pass photoacoustic spectrometer (PAS) is an important tool for the direct measurement of light absorption by atmospheric aerosol. Accurate PAS measurements heavily rely on accurate calibration of their signal. Ozone is often used for calibrating PAS instruments by relating the photoacoustic signal to the absorption coefficient measured by an independent method such as cavity ring down spectroscopy (CRD-S), cavity-enhanced spectroscopy (CES) or an ozone monitor. We report here a calibration method that uses measured absorption coefficients of aerosolized, light-absorbing organic materials and offer an alternative approach to calibrate photoacoustic aerosol spectrometers at 404 nm. To implement this method, we first determined the complex refractive index of nigrosin, an organic dye, using spectroscopic ellipsometry and then used this well-characterized material as a standard material for PAS calibration.

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Short summary
Accurate PAS measurements rely on accurate calibration of their signal. Ozone is often used for calibrating PAS instruments by relating the photoacoustic signal to the absorption coefficient measured by an independent method. We offer an alternative approach to calibrate photoacoustic aerosol spectrometers with aerosolized, light-absorbing organic materials. To implement this method, we first determined the complex refractive index of an organic dye, using spectroscopic ellipsometry.