This standard is applicable to instruments known as non-real time spectrum analyzers (hereinafter called "analyzers"). These instruments perform an analysis of the power distribution of a signal by a sampling process such as:
- Swept front end: superheterodyning in which the first local oscillator is swept.
- Swept I.F.: superheterodyning in which other than the first local oscillator is swept.
- Video detector tunable filter: analysis is accomplished by scanning the input filter across the signal in proportion to the CRT horizontal deflection with the detector output providing the vertical deflection.
Instruments known as real-time analyzers perform a continuous analysis of the incoming signal with the time sequence of events preserved between input and output. This standard is not applicable to those instruments.