deletions | additions       diff --git a/Problems_with_the_instrument_and__.tex b/Problems_with_the_instrument_and__.tex  index 26b0e90..96522e4 100644  --- a/Problems_with_the_instrument_and__.tex  +++ b/Problems_with_the_instrument_and__.tex 
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\begin{equation}  \label{eq:o2_dryair1}  column$_{O_2}$ column_{O_2}  = 0.2095 * column$_{dry air}$ column_{dry air}  \end{equation}  or  \begin{equation}  \label{eq:o2_dryair2}  \frac{column$_{O_2}$}{column$_{dry air}$} \frac{column_{O_2}}{column_{dry air}}  = 0.2095 \end{equation}  Retrieved variations from 0.2095 mol mol$^{-1}$ at TCCON sites must therefore be due to