Specific humidity or ERH or Calcium Carbide?

[Andy]

What is the most accurate or to be relied on?
From sensors placed in the floor, obtaining ERH levels, or calculating specific humidity (SH) and comparing it to ambient or undertaking a Speedy Calcium CARBIDE test? I am often coming across situations where ERH readings are up in the 90%'s, yet carbide and SH readings indicate bone dry? Can anyone answer this? ( Before anyone says, i have a method for undertaking the carbide test that does not allow distortion by heat from the drilling or crushing)