Stanford Research Systems SR785, Operating Manual And Programming Reference

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Display Setup Menu 4-41
SR785 Dynamic Signal Analyzer
Units
This display-only menu box shows the units of the active display. The units will depend
upon the measurement, the view, the Transducer Parameter settings, and the settings of
the <dB Units>, <Pk. Units>, <PSD Units>, <Phase Units>, and <dBm Ref. Imped>
softkeys.
dB Units
Determines whether a Log Mag view will be shown in dB (decibel) units. If off, no
decibel conversion will be performed. If set to 'On,' the measurement results will be
converted to decibels relative to the underlying units of the display. If the view is Log
Mag and dB Units is off, the graph will be shown with a logarithmic y-axis. If dB units is
on, the graph will be shown with a y-axis linear in dbs.
Setting this softkey to 'dBm,' will convert measurement results to decibels relative to 1
mW. The voltage to power conversion is done by assuming that power = volts
•
volts /
impedance where impedance is the setting of the <dBm Ref. Imped> softkey.
dBspl will convert measurement results to sound pressure level units. dBspl measures
sound pressure in decibels relative to a sound pressure of 20
µ
Pascals. dBspl is only
allowed if the Engineering Units for the corresponding input are set to Pascals.
Command: UNDB (?) d {, i}
Pk Units
Determines whether the active display units will be peak, peak to peak, or rms. This
softkey is inactive if the underlying measurement and view is unitless, e.g. frequency
response.
Command: UNPK (?) d {, i}