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Subject to change without notice
M e a s u r e m e n t s
8 Measurements
There are two different kinds of measurements on signals: cur
-
sor measurements and automatic measurements. All results
are stored in a buffer memory which is larger than the display
memory. The QuickView mode delivers all available parameters
of a signal curve. The integrated hardware counter shows the
count results on the selected channel.
8.1 Cursor measurements
The most frequently used measurement method with an oscil
-
loscope is the cursor measurement. This concept is oriented
towards the expected results and thus provides not only one or
two but in some modes, three cursors. Cursor measurements
are controlled by the keys: CURSOR MEASURE and the universal
knob. The kind of measurement can be defined in the menu
which will open upon pushing the key CURSOR MEASURE.
Fig. 8.1: Cursor measurements selection menu
The menu CURSOR MEASURE allows you to select cursor-
based measurements for an activated signal source on the
oscilloscope. The measurement source is indicated by the font
color of the respective result. The results are displayed at the
bottom of the screen. If “n/a” is displayed, the measurement is
not applicable to the signal. For instance, this may be the case
for a voltage measurement on a POD because only logic states
without voltage reference are displayed here. If “?” is displayed,
the display does not show a complete measurement result. For
instance, the
period to be measured may not display completely
and can consequently not be identified.
As shown above, the selection of the kind of measurement can
be done by pushing the respective soft menu key and selecting
the kind of cursor measurement with the universal knob. The
results will be displayed below the graticule. In order to move a
cursor, select the desired cursor by pushing the
universal knob
and position the cursor with the universal knob. The kinds of
measurements are:
VOLTAGE
This mode provides 2 cursors in order to measure 3 different
voltages. The values V
1
and V
2
represent the voltages differences
between the zero base line and the actual positions of the two
cursors on the selected signal curve. ΔV represents the voltage
difference between the cursors.
TIME
This mode provides 2 cursors in order to measure 3 different
times and an equivalent frequency. The values t
1
and t
2
represent
the times between the trigger and the position of the cursors.
Δt represents the time between the cursors.
RATIO X
This mode provides 3 cursors in order to measure ratios in X
direction (e.g. a
duty cycle) between the first and the second and
between the first and the third cursors. The values will be presen-
ted in 4 different formats: floating point, percent, degrees, radians.
RATIO Y
This mode provides 3 cursors in order to measure ratios in Y-
direction (e.g. an overshoot) between the first and the second
and between the first and the third cursors. The results will be
presented in 2 formats: floating point, percent.
COUNT
This mode provides 3 cursors in order to count signal crossings
of a level which can be set with the third cursor for a time span
as defined by the distance between the first and the second
cursors. The result will be presented in 4 different versions:
number of rising and falling level crossings, number of positive
and negative pulses.
PEAK LEVELS
peak levels
This mode provides 2 cursors in order to measure the minimum
and maximum values of a signal within the time span as defined
by the two cursors. The values Vp- and Vp+ represent the mi-
nimum and maximum values of the voltage. The peak-to-
peak
value (Vpp) is equal to the difference between the minimum and
maximum values.
RMS, MEAN, Standard deviation
,
σ
This mode provides 2 cursors in order to calculate the rms, the
mean and the standard deviation
σ
values of a signal between
the two cursors.
Duty cycle
This mode provides three cursors in order to calculate the duty
cycle of the signal between the two horizontal cursors. The
third vertical cursor will set the level at which the duty cycle
is determined.
Rise time 90%
This mode provides 2 cursors in order to measure the rise and fall
times between the two cursors. The rise and fall time are measured
between 10% to 90% of the signal amplitude.
Rise time 80%
This mode provides 2 cursors in order to measure the rise and fall
times between the two cursors. The rise and fall time are measured
between 20% to 80% of the signal amplitude.
V MARKER
V marker
This mode provides 2 cursors in order to measure two different
voltages and a time span. The values V1 and V2 represent the
voltages between the zero base line and the respective cursor.
ΔV represents the voltage difference between the two cursors.
Δt represents the time difference between them.
If the function
AUTOM. SOURCE
is activated (On), the currently
targeted channel will be used as source for the measurement.
If the setting is deactivated (Off), the channel set under SOURCE
will be applied even if it is not targeted. The soft menu key
SOURCE allows you to select a source for the measurement
by using the universal knob. Pressing the soft menu key
SET
TO TRACE
places the selected cursors in their optimal position
