This doesn't answer your question but wanted to share my experience on hygrometers with you. I'm in the process of putting together a wineador and have the newair 181. I ordered 2 of the xikar rectangular ones with the calibrate button. I stuck both in the boveda calibrating kit. Let them sit for 48 hours and both came out 5 off. I then ordered one of the hygroset rectangular and able to adjust the reading and threw it in the kit and it was off by 10 over. I had to adjust that one by 10 clicks which I think is the max. Threw it back in and still 2 over. My point is that neither brand was accurate like they say.
Hope you get it working properly.