Calibrating Hygrometer question

Hey guys, sorry for the newb question, but this is my first humidor. Anyway, I bought it from cuban crafters, holds 40 sticks and I am now prepping the whole thing. The hygrometer has read 80% humidity since I put into the bag with the salt and water mix. Its been 4 hours now and the instructions say wait at least 6. If it remains at 80% after 6 hours, what do I do?

Then it is off by 5%, just make note of it and subtract 5 from the reading. But if its an adjustable one, you can make the necesary adjustment so it will read correctly.

Thanks its more reading 81% but it said the hyrgometer should read around 75% so I will adjust the 6% accordingly. Thanks, I appreciate it.