First off, WELCOME SurfaceSteve!!! 
And good points.
I am not an installer but I can promise you I would take a $30 reader or two and put it in the slab before I put down a $75,000 floor....
1. To save my butt, and
B. because the flooring manufacturer expects the installer to verify the floor is ready for flooring.
We expect the installer to do this because they are the ones there at the moment, and they have the experience to advise. When a guy says 'Gee if we thought there would be a moisture issue we would have tested', that tells me the guy is ignorant of the major issue in the industry (does he ever read a trade magazine) or he slaps down product and collects a check and never uses the old bean.
I don't accept excuses from installers. It gets me in trouble, but I can handle it. As a professional installer you have to know you are doing the job correctly, and some testing is part of that.
Okay installers. Begin blasting, but remember I am on your side unless you just blindly toss down flooring and run.

And good points.
I am not an installer but I can promise you I would take a $30 reader or two and put it in the slab before I put down a $75,000 floor....
1. To save my butt, and
B. because the flooring manufacturer expects the installer to verify the floor is ready for flooring.
We expect the installer to do this because they are the ones there at the moment, and they have the experience to advise. When a guy says 'Gee if we thought there would be a moisture issue we would have tested', that tells me the guy is ignorant of the major issue in the industry (does he ever read a trade magazine) or he slaps down product and collects a check and never uses the old bean.
I don't accept excuses from installers. It gets me in trouble, but I can handle it. As a professional installer you have to know you are doing the job correctly, and some testing is part of that.

Okay installers. Begin blasting, but remember I am on your side unless you just blindly toss down flooring and run.
JD Grafton
Concrete Answers for Flooring Problems
JGrafton@ccsolves.com