Surface ozone analyzer

Since 2012, surface ozone concentration is measured at Chacaltaya with a Thermo Scientific 49i Ozone Analyzer.

The instrument is a UV photometric analyzer consisting of a dual-cell for differential measurements. As O3 molecules absorb UV light at a wavelength of 254 nm, the degree to which the UV light is absorbed is directly related to the ozone concentration (Beer-Lambert Law). The response time of this instrument is of 20 seconds, and at Chacaltaya data are stored with a one-minute resolution.

Automatic zero and span checks were performed daily until 2017, but due to an internal failure, zero checks started being performed manually every 2 weeks since 2018.

The instrument was calibrated against a traceable standard in 2017 at the WMO regional training center  (Argentina).

Contact person: Isabel Moreno

Ozone analyser Thermo Sci. 49i

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