chart constant in a sentence

1. The return values "'square root "'of \, \ mu _ 2 should correspond to the control chart constant d3, and Table IV confirms that this is indeed the case.
2. If \, \ phi ( x ) = \ Phi ( x ) is the standard normal distribution, " w " is known as the control chart constant d2 in the field of statistical process control.
3. It's difficult to find chart constant in a sentence.