Start here: A directional wattmeter separately samples forward- and reflected-traveling power in a transmission line.
Why it matters
Interchangeable elements or ranges may set frequency, direction, and power scale. Directivity limits reflected-power accuracy when the forward signal is much larger.
A practical example
Reversing the element or body changes which traveling wave the meter calls forward.
Use it well
Use the correct element and orientation, stay in range, zero or calibrate as required, and confirm with a known load.
Operating boundary
Keep the measurement reference plane, current program rules, land access, spectrum authorization, and exact packed configuration with the decision. A connector, meter reading, or program name alone does not establish readiness.
