Salt Calibration Questions

[bigloo]

I do 24 - 48 hrs. You are not actually waiting for the hygro to respond but for the conditions in the container to level off. I dont use a zip lock for this reason. I use a an air tight tuperware and I place the container into a closet out of the sun and make sure my air conditioner is on. Spikes in temperature can raise RH by releasing more humidity from the medium.