How to Calibrate a Hygrometer?

I have a Nappolion II Humidor, it came with a fancy looking analog hygrometer. I tried calibrating it with the steps I read here.
After 24 hours, the hygrometer read 45%. It has a flat head screw on the back, and when I turned it to adjust the level to 75% the whole thing spin in its casing, I eventually got it to 75%.

Also, I am currently seasoning the humidor. I filled up the humidifier, and placed 3 small bowls of distilled water, one in each drawer. I did this about 32 hours ago, and I placed the hygrometer in the humidor at the 24 hour mark.

The hygrometer currently reads 85%. Is this normal while seasoning? or is my hygrometer just malfunctioning. I plan to buy a digital hygrometer soon before I dare to put any cigars in.