22
Subject to change without notice
Controls and readout
Uncalibrated Settings / Overflow Indication
If the deflection coefficient is uncalibrated the READOUT
indicates e.g. “Y1>2V=” or “>500µs”. Such conditions
are indicated by a “>” or “<” sign automatically put in
front of the displayed measuring value.
Measurement range overflow (exceeding) is indicated in
front of the measuring value by the “>” sign.
Non executability of measurements
A question mark (?) is displayed if the measuring unit can‘t
find a useful value (e.g. frequency measurement without a
signal).
32.1 AUTO MEASURE
The table shows all menu items, sources and display abilities.
Their availability depends on the actual operating mode.
Voltage measurement is enabled only in combination with
AC or DC trigger coupling. DC input coupling is required
for DC voltage measurement and voltages with DC
content.
To avoid measuring errors the complete signal must be
displayed within the vertical graticule limits; i.e. without
over ranging.
Trigger signal
related measurement:
In the case of high frequency signals, the frequency
response of the trigger amplifier must be taken into
account; i.e. the measuring accuracy decreases at
increasing frequencies. Due to the different Y amplifier
and trigger amplifier frequency responses, there are also
deviations with respect to the signal display.
If relatively low frequency signals (< 20Hz) are present,
the measurement value continuously changes, following
the waveform. The pulse duty factor of such signals and
also the trigger slope setting will affect the measurement
result.
Frequency and Period measurement assume that the
trigger conditions are met (TR LED lit) and normal triggering
active for signals > 20Hz. Very low frequency signals require
a measurement time of several seconds.
Signal memory
(storage mode) related measurement:
Each displayed signal can serve as source for measu-
rement, except the reference signal or mathematic signal
in combination with addition (“add”) mode. The result is
calculated from the stored 8 bit signal data (memory
content). In contrast to analog signal based measurement
(trigger signal), this results in reduced measurement
accuracy.
Mean value (“avg”) and root mean square (“rms”)
calculation assume a minimum of one signal period of a
non complex waveform. In the case of complex signals,
the signal part (one period) must be determined by
CURSOR lines (CURSOR MEASURE).
1) Listing of all signal sources whose availability depends
on the operating conditions:
Y1
= trigger signal at trigger amplifier channel I output.
Y2
= trigger signal at trigger amplifier channel II output.
ext
= trigger signal at external trigger amplifier output.
AUTO MEASURE
