Wagner vs GE Hygromaster, Please Coment

[mferry4]

We are not accepting a 90-95% slab where product goes in at 80%.
The GC had an independent test with a GE Hygromaster and it read under 70%. What gives here? For fun, I took a calcium chloride test got a 3.61.
Whats wrong with the GE Hygromaster? Someone told me it did not satisfy the 2170?
The work will go to our competition. They will perform based on the independent's test results, with knowledge of these issues. Any comments would be appreciated.