Portable calibrator for NO based on the photolysis of N<sub>2</sub>O and a combined NO<sub>2</sub>∕NO∕O<sub>3</sub> source for field calibrations of air pollution monitors
<p>A highly portable calibration source of nitric oxide (NO) based on the photolysis of nitrous oxide (<span class="inline-formula">N<sub>2</sub>O</span>) supplied by 8 or 16 g disposable cartridges is demonstrated to serve as an accurate and reliab...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2020-03-01
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| Series: | Atmospheric Measurement Techniques |
| Online Access: | https://www.atmos-meas-tech.net/13/1001/2020/amt-13-1001-2020.pdf |
| Summary: | <p>A highly portable calibration source of nitric oxide (NO) based on
the photolysis of nitrous oxide (<span class="inline-formula">N<sub>2</sub>O</span>) supplied by 8 or 16 g disposable
cartridges is demonstrated to serve as an accurate and reliable transfer
standard for the calibration of NO monitors in the field. The instrument
provides output mixing ratios in the range 0–1000 ppb with a precision and
accuracy better than the greater of 3 ppb or 3 % of the target NO
mixing ratio over a wide range of environmental conditions of ambient
temperature (8.5–35.0 <span class="inline-formula"><sup>∘</sup></span>C), pressure (745–1015 mbar corresponding
to 2.7–0.0 km of elevation), and relative humidity (0 %–100 % RH). The combination
of the NO calibration source with a previously described ozone calibration
source based on the photolysis of oxygen in air provides a new instrument
capable of outputting calibrated mixing ratios of NO, ozone (<span class="inline-formula">O<sub>3</sub></span>), and
nitrogen dioxide (<span class="inline-formula">NO<sub>2</sub></span>), where the <span class="inline-formula">NO<sub>2</sub></span> is produced by the
stoichiometric gas-phase reaction of NO with <span class="inline-formula">O<sub>3</sub></span>. The portable
<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M9" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msub><mi mathvariant="normal">NO</mi><mn mathvariant="normal">2</mn></msub><mo>/</mo><mi mathvariant="normal">NO</mi><mo>/</mo><msub><mi mathvariant="normal">O</mi><mn mathvariant="normal">3</mn></msub></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="65pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="1de30a4787f90cc6b8f7a18095c3f554"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="amt-13-1001-2020-ie00003.svg" width="65pt" height="14pt" src="amt-13-1001-2020-ie00003.png"/></svg:svg></span></span> calibration source requires no external gas cylinders
and can be used for calibrations of NO, <span class="inline-formula">NO<sub>2</sub></span>, and <span class="inline-formula">O<sub>3</sub></span> instruments for
mixing ratios up to 1000, 500, and 1000 ppb, respectively. This portable
calibrator may serve as a convenient transfer standard for field
calibrations of ozone and <span class="inline-formula">NO<sub><i>x</i></sub></span> air pollution monitors.</p> |
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| ISSN: | 1867-1381 1867-8548 |