11
Subject to change without notice
with steep edges) we strongly advise using the probes
HZ51
(x10)
HZ52
(x10 HF) and
HZ54
(x1 and x10). This can save the
purchase of an oscilloscope with larger bandwidth.
The probes mentioned have a HF-calibration in addition to low
frequency calibration adjustment. Thus a group delay correction
to the upper limit frequency of the oscilloscope is possible
with the aid of an 1MHz calibrator, e.g.
HZ60
.
In fact the bandwidth and rise time of the oscilloscope are not
noticeably changed with these probe types and the waveform
reproduction fidelity can even be improved because the probe can
be matched to the oscilloscopes individual pulse response.
If a x10 or x100 attenuator probe is used, DC input
coupling must always be used at voltages above 400V.
With AC coupling of low frequency signals, the
attenuation is no longer independent of frequency,
pulses can show pulse tilts. Direct voltages are
suppressed but load the oscilloscope input coupling
capacitor concerned. Its voltage rating is max. 400 V
(DC + peak AC). DC input coupling is therefore of quite
special importance with a x100 attenuation probe
which usually has a voltage rating of max. 1200 V (DC
+ peak AC). A capacitor of corresponding capacitance
and voltage rating may be connected in series with the
attenuator probe input for blocking DC voltage (e.g. for
hum voltage measurement).
With all attenuator probes, the maximum AC input voltage
must be derated with frequency usually above 20kHz.
Therefore the derating curve of the attenuator probe type
concerned must be taken into account. The selection of
the ground point on the test object is important when
displaying small signal voltages. It should always be as
close as possible to the measuring point. If this is not done,
serious signal distortion may result from spurious currents
through the ground leads or chassis parts. The ground
leads on attenuator probes are also particularly critical.
They should be as short and thick as possible. When the
attenuator probe is connected to a BNC-socket, a BNC-
adapter, should be used. In this way ground and matching
problems are eliminated. Hum or interference appearing
in the measuring circuit (especially when a small deflection
coefficient is used) is possibly caused by multiple
grounding because equalizing currents can flow in the
shielding of the test cables (voltage drop between the
protective conductor connections, caused by external
equipment connected to the mains/line, e.g. signal
generators with interference protection capacitors).
Controls and readout
Controls and Readout
A: Basic settings
The following description assumes that:
1. “Component Tester” is switched off.
2. The following settings are present under
MAIN MENU > SETUP & INFO > MISCELLANEOUS:
2.1 CONTROL BEEP and ERROR BEEP activated (x),
2.2 QUICK START not activated.
3. The screen Readout is visible.
The LED indicators on the large front panel facilitate operation
and provide additional information. Electrical end positions of
controls are indicated by acoustic signal (beep).
All controls, except the power switch
(POWER)
, are
electronically set and interrogated. Thus, all electronically set
functions and their current settings can be stored and also
remotely controlled.
B: Menu Display and Operation
Operation of some pushbuttons activates the display of menus.
There are Standard and Pulldown Menus.
Standard menus:
When a standard menu is displayed, all other readout
information (e.g. parameter settings) are switched off. The
readout then consists of the menu headline, and the respective
menu functions. At the bottom of the graticule are displayed
symbols and commands which can be operated by the
pushbuttons related to them below.
“
Esc
”
switches one step back in the menu hierarchy.
“
Exit
”
closes the menu and switches back to the operating
conditions present before calling the menu.
“
Set
”
calls the selected menu item or starts a function.
“
SAVE
” results in storage.
“
Edit
”
calls the edit menu.
The pushbuttons below the triangle and arrow symbols select
one item that is then highlighted. If in addition “Use INT./FOC.
knob to select” is displayed, the INT./FOC. knob can be used
to select within the item. Where a “[ ]” symbol appears in an
activated line, a “[x]/[ ]” symbol is displayed with the other
command symbols at the bottom of the screen. The
pushbutton below the symbol is used for switchover (toggle).
Pulldown menus:
After pressing a pushbutton which calls a pulldown menu, the
instrument parameter settings are still displayed. The readout
only changes in respect to the called parameter (e.g. input
coupling) and now shows all selectable parameter options (in
case of input coupling: AC, DC and GND). The previously
displayed parameter doesn‘t change but is displayed
highlighted. Each time the pushbutton is briefly pressed the
next parameter becomes active and highlighted, as long as
the pulldown menu is displayed. Without further pressing of
the pushbutton, the pulldown menu extinguishes after a few
seconds and the selected parameter, the CURSOR line(s) and
the measuring result are displayed in the normal way.
C: READOUT Information
The readout alphanumerically displays the scope parameter
settings, measurement results and CURSOR lines. Which
information is displayed depends on the actual instrument
settings. The following list contains the most important display
information.
Top of the graticule from left to right:
1. time deflection coefficient and additionally the sampling
rate in digital mode.
