Is this the one you have?
Rain:The unit says this, as a selling point: "One step calibration button. Push and hold for 5 seconds and unit self-calibrates.".
Calibrates to what? I hope it means if I throw it in the boveda calibration bag (75%rh), then hitting calibrate will make it 75, NOT what the unit "thinks" is correct.
jadelt:Mine usually varies a little.... that is within the +/- 2% range though..... close enough for me.