Long-term reliability of the Figaro TGS 2600 solid-state methane sensor under low-Arctic conditions at Toolik Lake, Alaska
The TGS 2600 was the first low-cost solid-state sensor that shows a response to ambient levels of CH 4 (e.g., range ≈1.8 –2.7 µmol mol −1 ). Here we present an empirical function to correct the TGS 2600 signal for temperature and (absolute) humidity effects and address the long-term reliability of t...
| Published in: | Atmospheric Measurement Techniques |
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| Main Authors: | , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Copernicus Publications
2020
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| Subjects: | |
| Online Access: | https://doi.org/10.5194/amt-13-2681-2020 https://doaj.org/article/83771f817d924dc6a2693822f04365b2 |
| Summary: | The TGS 2600 was the first low-cost solid-state sensor that shows a response to ambient levels of CH 4 (e.g., range ≈1.8 –2.7 µmol mol −1 ). Here we present an empirical function to correct the TGS 2600 signal for temperature and (absolute) humidity effects and address the long-term reliability of two identical sensors deployed from 2012 to 2018. We assess the performance of the sensors at 30 min resolution and aggregated to weekly medians. Over the entire period the agreement between TGS-derived and reference CH 4 mole fractions measured by a high-precision Los Gatos Research instrument was R 2 =0.42 , with better results during summer ( R 2 =0.65 in summer 2012). Using absolute instead of relative humidity for the correction of the TGS 2600 sensor signals reduced the typical deviation from the reference to less than ±0.1 µmol mol −1 over the full range of temperatures from −41 to 27 ∘ C . At weekly resolution the two sensors showed a downward drift of signal voltages indicating that after 10–13 years a TGS 2600 may have reached its end of life. While the true trend in CH 4 mole fractions measured by the high-quality reference instrument was 10.1 <math xmlns="http://www.w3.org/1998/Math/MathML" id="M13" display="inline" overflow="scroll" dspmath="mathml"><mrow class="unit"><mi mathvariant="normal">nmol</mi><mspace linebreak="nobreak" width="0.125em"/><msup><mi mathvariant="normal">mol</mi><mrow><mo>-</mo><mn mathvariant="normal">1</mn></mrow></msup><mspace linebreak="nobreak" width="0.125em"/><msup><mi mathvariant="normal">yr</mi><mrow><mo>-</mo><mn mathvariant="normal">1</mn></mrow></msup></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="76pt" height="15pt" class="svg-formula" dspmath="mathimg" md5hash="73ee9520c8d75acdb95d28bc5e4da24c"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" ... |
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