I recently checked the humidity level and the sealing of the basement. I used aluminum foil for this. Approximately 1 square foot required. The foil must be attached to the wall and wait 24 hours. If condensation appears on the outside of the foil, then the basement humidity is increased. This can be corrected with a dryer. If condensation appears on the inside of the foil, this indicates that the ground around the foundation is very wet. In this case, it is best to seal the room. I learned about this method from this site https://www.pomwaterproofing.ca/best-exterior-basement-waterproofing/ . Read the blog! You will find a lot of important information for yourself!