Diffusion coefficients in sorbent sheets (Ds) can be measured by bringing a spiked sheet in contact with unspiked sheets and measuring concentrations in the stacked sheets after some time. Models for the concentration distribution in the sheets are described by Crank (The mathematics of Diffusion, 1975).
Present spreadsheet template helps with calculating diffusion coefficients from experimental data using nonlinear least squares.
Features of the template are
- Up to 10 unspiked sheets and 1 spiked sheet (all sheets have equal thickness)
- For configurations with spiked sheet at top or center of the stack
- Estimation of logDs and its standard error
- Graphical output of experimental and modeled concentrations
- Graphical output of residual errors
- Missing data allowed
- Manual with scientific background and operating instructions available
- No macros
- Programming code can be inspected and modified
Templates for more complex configurations (single or multiple spiked sheets at any position in the stack, and/or stacks with non-uniform sheet thicknesses) available on request.