Thanks for all the input. I will buy a decent thermometer/Hygrometer so I can do valid comparisons. I plan this fall to do what ever it takes to make my house comfortable. I need to 1st find a good tech in my area. I see you guys are having your convention here in Baltimore. I live in Finksburg Maryland about 30 minutes from downtown. If you all want to come out and debate what I should do with my system I'll buy the crabs and beer.
I took a half dozen cheap humidity meters and one day when I had nothing better to do, tested them against one another in a variety of locations. One would think if the measurements would agree closely with one another, that the meters would be pretty accurate.
I know, I know. What I tested was not directly the accuracy of these meters, but the consistency of one meter's measurements vs. anothers. But I consider it significant that with this test sample, the largest errors I observed was less than 5% off of the average. This was in a range of 40% to 66% RH.
The proposal to make a test environment using salt and a baggie, I respect that as useful information. However I must point out that homes usually need accuracy in the range of 45-65%, and I have not seen a test environment for that. My tests tell me that accuracy of these cheap meaters varies considerably across the range.
BTW my favorite meter is one for $16 at Walmart. Have not found one as cheap as some have quoted. I would like very much to have more remote wireless meters, but Radio Shack's price on additional remotes is too rich for my taste. Of course one could buy a true scientific instrument as a friend did, but he paid rather more.
Hope this helps -- P.Student
I use a sling.... RH is a calculation based on DB and WB.
I would suggest raising the temp from 70 to 74 just to give it a try, the higher temperature will equal a lower humidity. This test simply will not cost you a nickle.