[eaadams]

Has anyone (like concrete construction) published a series of RH tests using 4.0 & 5.0 tests over time in the same slab?  
I'm wondering if the 5.0 probes get lower readings than the 4.0.  I know that one of the testing companies in my area that uses (non wagner) reusable probes always seems to get results slightly lower than mine.

[rapidrhrep]

Evan:

The 4.0 and the 5,0, really, are exactly the same. Same isolation fins at the bottom, same sensor, same sensor height from bottom of the hole. If you put the two of them side by side, except for color, you really would not know the difference. The only thing we changed was how the plastic separates. Regarding lower readings, if they are using -11 compliant sensors and/or sleeves and doing the testing per the standard, readings should be within 2-3%RH. Hope this helps.