harmonize isotherm data

[kjappelbaum]

common between the experiments should be:

• sample weight
• p
• p/p0
• temperature
• adsorptive
• (measurement type: adsorption/desorption)

[kjappelbaum]

also, we should take either a filepath or a string for all kinds of data (or offer both options). Due to the excel sheet we probably should default to taking a filepath.

[kjappelbaum]

save x and y units

[kjappelbaum]

check also compatibility with https://adsorption.nist.gov/isodb/index.php

[kjappelbaum]

so now we will have as x always relative pressure p/p0 and as y the excess adsorption in mmol / g.

if we have a desorption / cycle we make a new jcamp. Adsorption will be the datatype Adsorption Isotherm and desorption will be Desorption Isotherm.

for the jcamp we will use the following keys: x: pressure relative to saturation pressure
y: excess adsorption mmol/g p: absolute pressure in kPa r: Excess Adsorption [%]

We use relative pressure for x as it is

• probably more meaningful in PCA
• we do not have access to the nature of the gas and absolute pressure from some files. There, we only have the relative pressure.