If you keep water in the incubator tray and keep the temperature right, the humidity should take care of itself, if you keep it in a controlled environment.
All I know about Australia is that Paul Hogan came from there. Crocodile Dundee. LOL
So, GO HERE and look at these instruments, if your temp in the room fluctuates a lot.
I have to keep my incubator dry or I end up with drowned gooey chicks, so that doesn't work for everyone.