HP 8591C User Manual page 344

measurement range
The ratio, expressed in dB, of the maximum signal level that can be
measured (usually the maximum safe input level) to the lowest achievable
average noise level. This ratio is almost always much greater than can be
realized in a single measurement. Refer also to dynamic range.
memory
A storage medium, device, or recording medium into which data can be
stored and held until some later time, and from which the entire original
data may be retrieved.
memory card
A small, credit-card-shaped memory device that can store data or
programs. The programs are sometimes called personalities and give
additional capabilities to your instrument. Typically, there is only one
personality per memory card. Refer also to personality.
menu
The analyzer functions that appear on the display and are selected by
pressing front-panel keys. These selections may evoke a series of other
related functions that establish groups called menus.
modem
A device that enables a computer to interface with another computer
or analyzer over the telephone connection. Modem is an acronym for
modulator and demodulator.
non-interfering measurements
Measurements made without turning off modulation or the carrier (Option
107 required).
nonvolatile memory
Memory data that is retained in the absence of an ac power source. This
memory is typically retained with a battery. Refer also to battery-backed
RAM.
normalized reference level
An amplitude level representing 0 dB deviation from a calibrated system's
response. It is obtained by subtracting the system's response from itself.
Glossary- 11