Lesson 6 of 29 · 6 min read
Knowing normal
A reading only means something next to what it is supposed to be. Here is where that number comes from, and where to find it on the machine in front of you.
This lesson is part of the course
Readings are scored to your account. The Check Yourself questions at the end of each one count toward your certificate. Sign in to read this one and keep the record.