nwrichmond / sedsettle Goto Github PK

When the settling tube system was first set up, in 2018, a mass-produced sand standard was analyzed. Results agreed with known grain size of the standard (20-30 ASTM is roughly 0.5 phi). However, when this standard was run again in 2019 and in 2020, the program yielded dramatically incorrect grain sizes (see figure). It is unclear why this is the case. It might be related to code tweaks done in 2019. @NWRichmond, do you have any ideas? I have read through the code and am stumped. I think the fundamental issue is related to how elapsed time is communicated or calculated -- the first arrival of grains on the weigh-plate recorded in "data_mass_timeseries" is earlier than the actual time it took for grains to hit the weigh-plate (as measured with a stop watch).