I need to measure humidity in a variety of caves. I've noticed that some cave researchers use Sling Psychrometers, but I've read that they have some accuracy problems with temperatures 80 to 100 degrees F. I've also read that some people prefer the Digital Psychrometers/Hygrometers. The prices on these range hugely from $5 to hundreds of dollars, but it is hard to guess which ones are accurate. I want a sturdy, light-weight unit to carry in the field and take one-time measurements in each cave.
Can anyone make suggestions? Thanks!