Graphed data showing 2 sponge soundhole humidifiers lasted a bit over 3 weeks before drying out, compared to Musik Tent expected to go several more months on current fill of distilled water. And no case needed.
The second graph shows results inside the case, where humidity variation was as high as 20% RH on low ambient humidity days, with lowest reading at headstock and highest in soundhole. This seems to indicate the headstock area of the case is less insulated from the outside humidity than other areas of the case.
Damon DeBusk is a multi-patented product designer, process and quality engineer, project manager, author, and inventor of Musik Tent Instrument Humidors and HumiForm Cigar Humidifiers.