An experimental method for characterizing a thermal conductivity cell for use in adsorption measurements by the carrier gas method is described. A three parameter equation is derived and experimentally proven, and the parameters are evaluated. Measurements are made with various concentrations of a nitrogen-hydrogen mixture from 0 to 100% nitrogen content. Four types of operating modes are compared. The mode which proves the best is the controlled resistance mode, which has a linear response for nitrogen concentrations ranging from the ppm level up to 100%. The error to be expected in gas chromatographic (GC) or sorptometric applications due to deviation from linearity is less than 0. 5% for peak amplitudes up to 22% and does not exceed 2. 2% with peaks ranging from zero to 100%.
ASJC Scopus subject areas
- Analytical Chemistry