Journal cover Journal topic
Atmospheric Measurement Techniques An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

IF value: 3.668
IF 5-year value: 3.707
IF 5-year
CiteScore value: 6.3
SNIP value: 1.383
IPP value: 3.75
SJR value: 1.525
Scimago H <br class='widget-line-break'>index value: 77
Scimago H
h5-index value: 49
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

  03 Aug 2020

03 Aug 2020

Review status
A revised version of this preprint was accepted for the journal AMT and is expected to appear here in due course.

Effect of Polyoxymethylene (POM-H Delrin) offgassing within Pandora head sensor on direct sun and multi-axis formaldehyde column measurements in 2016–2019

Elena Spinei1, Martin Tiefengraber2,3, Moritz Müller2,3, Manuel Gebetsberger2, Alexander Cede2, Luke Valin4, James Szykman4, Andrew Whitehill4, Alexander Kotsakis5, Fernando Santos6, Nader Abbuhasan7, Xiaoyi Zhao8, Vitali Fioletov8, Sum Chi Lee8, and Robert Swap9 Elena Spinei et al.
  • 1Center for Space Science And Engineering Research, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
  • 2LuftBlick, Innsbruck, Austria
  • 3Department of Atmospheric and Cryospheric Sciences, University of Innsbruck, Innsbruck, Austria
  • 4United States Environmental Protection Agency, Durham, NC, USA
  • 5Universities Space Research Association, Columbia, MD, USA
  • 6Earth System Science Interdisciplinary Center, University of Maryland, College Park, MD, USA
  • 7Joint Center for Earth Systems Technology, University of Maryland, Baltimore County, Baltimore, USA
  • 8Air Quality Research Division, Environment and Climate Change Canada, Toronto, M3H 5T4, Canada
  • 9NASA Goddard Space Flight Center, Greenbelt, MD, USA

Abstract. Analysis of formaldehyde measurements by the Pandora spectrometer systems between 2016 and 2019 suggested that there was a temperature dependent process inside Pandora head sensor that emitted formaldehyde. Some parts in the head sensor were manufactured from thermal plastic polyoxymethylene homopolimer (E.I. Du Pont de Nemour & Co., USA: POM-H Delrin®) and were responsible for formaldehyde production. Laboratory analysis of the four Pandora head sensors showed that internal formaldehyde production had exponential temperature dependence with a damping coefficient of 0.0911 ± 0.0024 °C−1 and the exponential function amplitude ranging from 0.0041 DU to 0.049 DU. No apparent dependency on the head sensor age and heating/cooling rates was detected.

The total amount of formaldehyde internally generated by the POM-H components and contributing to the direct sun measurements were estimated based on the head sensor temperature and solar zenith angle of the measurements. Measurements in winter, during cold days in general and at high solar zenith angles (> 75 °) were minimally impacted. Measurements during hot days and small solar zenith angles had up to 1 DU contribution from POM-H parts. Multi-axis differential slant column densities were minimally impacted (< 0.01 DU) due to the reference spectrum collected within a short time period with a small difference in head sensor temperature.

Three new POM-free Pandora head sensors (manufactured in summer 2019) were evaluated for temperature dependent attenuation across the entire spectral range (300 to 530 nm). No formaldehyde or any other absorption above the instrumental noise was observed across the entire spectral range.

Elena Spinei et al.

Elena Spinei et al.

Elena Spinei et al.


Total article views: 164 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
108 51 5 164 9 9
  • HTML: 108
  • PDF: 51
  • XML: 5
  • Total: 164
  • BibTeX: 9
  • EndNote: 9
Views and downloads (calculated since 03 Aug 2020)
Cumulative views and downloads (calculated since 03 Aug 2020)

Viewed (geographical distribution)

Total article views: 184 (including HTML, PDF, and XML) Thereof 184 with geography defined and 0 with unknown origin.
Country # Views %
  • 1



No saved metrics found.


No discussed metrics found.
Latest update: 27 Nov 2020
Publications Copernicus
Short summary
Plastics are widely used in everyday life and scientific equipment. This paper presents Delrin plastic offgassing as a function of temperature on the atmospheric measurements of formaldehyde by Pandora spectroscopic instruments. The sealed telescope assembly containing Delrin components emitted large amounts of formaldehyde at 30–45 °C significantly interfering with the Pandora measurements. These results have a broader implication since electronics products often experience the same temperatures.
Plastics are widely used in everyday life and scientific equipment. This paper presents Delrin...