The Treaty of Waitangi is an agreement that was signed by the British Crown and Māori in 1840, enabling the British settlers and Māori people to live together under a common set of laws. – nzhistory.govt.nz
Like any other document, it is susceptible to relative humidity. Mould can occur and a fluctuation can expand and contract the structure of the paper. National archive storage’s of records 30 years and older in climatic regions: 20°C ± 2°C 50%RH ± 5, were connected to 4 RA and DC series units to stabilise the humidity.
Another national treasure is the score board at Eden park NZ, which was threatened by moisture in electronics which can affect the high-tech display. Model DC31 was able to control to 35%rh within the enclosure.
Eden Park – Source (https://www.flickr.com/photos/kiwi/)
Unfortunately the dehumidifier is too reliable to avoid recent scores with the Wallabies VS All Blacks…