Reduced drift, high accuracy stable carbon isotope ratio measurements using a reference gas with the Picarro G2101-<em>i</em> gas analyzer

Reduced drift, high accuracy stable carbon isotope ratio measurements using a reference gas with the Picarro G2101-i gas analyzer

A methodology and guide to further reducing the analzyer drift dramatically by referencing the measurements to a secondary or working gas standard. 

Abstract: 

The Picarro G2101-i gas analyzer provides exceptionally low drift measurements right out of the box, allowing field measurements of the stable isotope ratio 13CO2 with a precision of 0.3 permil in five minutes, and a drift of about 1-2 permil in a 24 hour period. For more demanding applications, it is possible to reduce the drift dramatically by referencing the measurements to a secondary or working gas standard. In this white paper we describe a method for employing a working standard to improve the measurement precision to below 0.1 permil. If the working standard is also traceable to a primary reference scale, this precision can translate into an overall accuracy of better than 0.1 permil.