HP 8591C, Руководство пользователя, Страница: 340 / 373

the instrument, is classified as ROM (read-only memory). The Ermware
determines the operating characteristics of the instrument or equipment.
Each firmware version is
by a revision code number, or date
code.
FM deviation
Peak deviation of the audio FM signal of a cable TV channel.
frequency accuracy
The uncertainty with which the frequency of a signal or spectral
component is indicated, either in an absolute sense or relative to some
other signal or spectral component. Absolute and relative frequency
accuracies are
independently.
frequency range
The range of frequencies over which the analyzer performance is
The maximum frequency range of many microwave analyzers
can be extended with the application of external mixers.
frequency resolution
The ability of an analyzer to separate closely spaced spectral components
and display them individually. Resolution of equal amplitude components
is determined by resolution bandwidth. Resolution of unequal amplitude
signals is determined by resolution bandwidth and bandwidth selectivity.
frequency response
The peak-to-peak variation in the displayed signal amplitude over a
center frequency range. Frequency response is typically
in terms of
relative to the value midway between the
extremes. It also may be relative to the calibrator signal.
frequency span
The magnitude of the displayed frequency component. Span is
represented by the horizontal axis of the display. Generally, frequency
span is given as the total span across the full display. Some analyzers
represent frequency span (scan width) as a per-division value.
frequency stability
Stability is the ability of a frequency component to remain unchanged
in frequency or amplitude over short- and long-term periods of time.
Stability refers to the local oscillator’s ability to remain Exed at a
particular frequency over time. The sweep ramp that tunes the local
oscillator influences where a signal appears on the display. Any long-term
Glossary-7