What the label leaves out
In impedance it distinguishes inductive from capacitive reactance; in reflection coefficient it locates the load around a constant-magnitude circle. The reference and sign convention must be known.
The mistake to avoid
A phase number without frequency, reference plane, convention, and associated magnitude is not actionable. Cable length alone can rotate it dramatically.
A sound installation approach
Record the complete complex quantity, calibrate at the required plane, confirm units and convention, unwrap phase when appropriate, and compare only measurements made under controlled geometry.
Use current manufacturer documentation, measured RF behavior, the building grounding system, and applicable electrical and lightning requirements. A ratio, DC continuity check, or inline protective device does not establish complete-system safety or efficiency.
