Hameg HM504-2, Manual

Page: 23 / 42

21
Subject to change without notice
1/
∆∆∆∆∆
t (display “1/
∆
t: measured value“)
Two vertical CURSOR lines enable frequency measurement
in Yt mode (not in XY mode). Briefly pressing the UNIT
[35]
pushbutton directly switches over from 1/
∆∆∆∆∆
t to
∆∆∆∆∆
t (time)
measurement and vice versa.
Rise Time (display “tr 10: measured value”)
Rise time measurement by aid of two horizontal CURSOR
lines and two “+” symbols which have the following meaning.
1
st
Lower CURSOR line = 0%.
2
nd
Lower “+” symbol = 10% of the CURSOR lines
distance.
3
rd
Upper “+” symbol = 90% of the CURSOR lines
distance.
4
th
Upper CURSOR line = 100%.
SET [32] enables an automatic signal related CURSOR line
setting (in DUAL mode related to the signal used for triggering),
which can later be changed manually.
The distance between the “+” symbols and the CURSOR
lines are set automatically. For rise time measurement the
horizontal position of the “+” symbols must be set manually
to the signal slope. This requires that the CURSOR POS is
active and each “+” symbol is marked (“I”, “II”) by the aid
of the SELECT
[34] function.
Note: For maximum “+” symbol positioning and measuring
accuracy first set the signal slope to the screen centre X-
POS.
[12] and then activate X-magnifier X-MAG. x10 [13].
To avoid CURSOR line and “+” symbol changes after each
change of a signal position in X and/or Y direction, a fixed
relation between signal and CURSOR display can be made by
activating the GLUE (33) function. GLUE is indicated by a
reduced number of dots in the CURSOR lines and the “+”
symbols.
Further information about this item can be found in this
manual under “Type of signal voltage” in section “Rise Time
Measurement”.
∆∆∆∆∆
V (display
∆
V: channel, measured value)
CURSOR supported voltage measurement.
In Yt (time base) mode two horizontal CURSOR lines are
displayed: Single channel (CH I or CH II) mode automatically
relates one signal and the CURSOR lines. The measurement
value is connected with the Y deflection coefficient.
DUAL mode requires selection between channel I and II with
the SOURCE -pushbutton
[33] . The CURSOR line must be
placed on the signal (channel) chosen by the SOURCE
function.
Addition (“add”) mode requires equal Y deflection coefficients
for both channels.
XY mode causes the display of two vertical or horizontal
CURSOR lines: The SOURCE-pushbutton
[33] allows selection
between X (CH I) and Y (CH II) voltage measurement. In the
case of X voltage measurement, vertical CURSOR lines are
displayed.
V to GND (display V: channel, measured value)
One CURSOR line is displayed for voltage measurement
related to the trace 0 Volt position. This is the only exception
to the description of item
∆
V.
Ratio X (display “ratio:X, measured value, unit”)
Ratio X measurement causes the display of two long and one
short CURSOR lines and is enabled in Yt (time base) mode only.
The unit to be displayed must be selected by briefly pressing
the UNIT
[35] pushbutton to call the UNIT menu. Then the
following units are being offered: ratio, %, ° (angle unit:
degree of angle and pi.
The long CURSOR line in the left position always serves as
reference line. A “–“ (minus) sign indicates measurement
results if the short CURSOR line is placed left of the reference
line.
Ratio:
Enables the measurement of pulse duty ratio. The distance
between the long CURSOR lines is equivalent to1 (whole
cycle).
Example for a pulse signal with 4 div. pulse and 1 div. space:
The long CURSOR lines must coincide with the start position
of first and the second pulse (distance = 5 div.) as the
reference distance (1). Then the “I” symbol must be assigned
to the short CURSOR line SELECT
[34] which must then be
set to the pulse end position (4 div. after the pulse start).
Corresponding to the ratio of pulse duration to period length
(4:5 = 0.8) “0.8” will be displayed.
%:
Same function as described before under “Ratio”. The
measurement result is displayed in % (unit).
° :
Angle measurement referring to the CURSOR line distances.
The distance between the long CURSOR lines should cover
one signal period, equivalent to 360°. Angle measurement
then can be performed by shifting the short CURSOR line.
Additional information can be found in section “Operating
modes of the vertical amplifiers in Yt mode” under “Phase
difference measurement in DUAL mode”.
pi:
Determination of the value for “pi” referring to the CURSOR
line distances. The equivalent for “2 pi” is one sine wave
period; thus the distance between the long CURSOR lines
must be 1 period. If the distance between the long CURSOR
in left hand position and the short CURSOR line referring to
it is 1.5 periods, “3 pi” will be indicated.
Ratio Y (display “ratio:Y, measured value, unit”)
Ratio Y measurement causes the display of two long and one
short CURSOR lines and is enabled only in Yt (time base)
mode.
Briefly pressing the UNIT-pushbutton
[35] switches over
between the ratio (unnamed) and ratio in %.
The long CURSOR line in the lower position always serves as
the reference line. A “–“ (minus) sign indicates measurement
results if the short CURSOR line is placed below the
reference line.
Ratio: The distance between both long CURSOR lines is
equivalent to1.
Example: If the distance between the long CURSOR lines is
6 div. and the short CURSOR line is activated SELECT
[34]
and set 4 div. above the reference CURSOR line, the ratio is
4:6, causing “0.667” (without unit) to be displayed.
%:
The only difference between previous item “Ratio” and “%”
is that the distance between the long CURSOR lines is
equivalent to100% and the measuring result is displayed as
a % value.
Controls and Readout