User manual
39
Analysis
the key COPY CHANNEL to copy the current signal into a
mask memory. The mask displays in white and appears as
an overlay of the output signal. The menu keys Y-POSITION
and STRETCH Y enable you to shift this curve vertically or
to enlarge it. The two menu items WIDTH Y and WIDTH
X allow you to set the tolerance for the mask. The univer-
sal knob or the KEYPAD button in the CURSOR/MENU sec-
tion are used to enter values with a resolution of 1/100 divi-
sion. A mask includes a minimum and a maximum value for
each captured data value. The minimum and maximum va-
lue for a source curve with only one value per data are iden-
tical. The width indicates the distance between the periphe-
ral points and the original point. The greater the selected va-
lue is, the greater are the potential curve deviations in the
amplitude. The tolerance mask is displayed in white in the
background. The generated and edited mask can be used
immediately for the test, however, it is only saved tempora-
rily in the instrument storage. The soft menu key SAVE can
be used to store the mask permanently to a USB stick or to
the internal memory. Press the key MENU OFF to return to
the start menu.
PressthesoftmenukeyLOADMASKtoopenalebrowser
which allows you to load previously stored masks for the
test(leextension.HMK).Aloadedmaskcanbechanged
inthemenuNEWMASK.Changeswillbeappliedtothele
when the mask is edited and saved. Pressing the soft menu
key ACTIONS in the PASS/FAIL main menu opens a menu
with the available actions. The following four actions can be
performed:
❙ Audio signal if the tolerance limits have been exceeded
❙ Stopforrst-timefailure(numberisadjustable)
❙ Pulseforrst-timefailure(emitsapulseattheAUXoutput
in case of failure)
❙ Screendumpforrst-timefailureonUSB stick
❙ Screendumpforrst-timefailureonprinter
An action is performed if the respective condition is met
(e.g.aspecicnumberofmaskfailures).Eachactionisas-
signedauniqueconditionwhichcanbedenedseparately
from the other actions. The respective condition can be de-
nedinthemenuforthecorrespondingaction.Selectthe
respective action by pressing the appropriate soft menu
key; the corresponding soft menu item will be highlighted in
blue. Press the MENU OFF key to return to the main menu
and to start the mask test.
9.5 Component test
9.5.1 General
The R&S®HMO Compact series has a built-in component
tester. This can be activated by pushing the XY/CT button
(VERTICAL section) with the soft menu key CT. The unit un-
der test is connected to the two contacts below the screen.
After switch on the component tester mode, the Y preamp-
liersandthetime base are disconnected. While using the
component tester, signals may be present at the inputs as
long as the unit under test is not connected to any other cir-
cuit. It is possible to test components remaining in their cir-
cuits, but in such cases all signals must be disconnected
from the front panel BNC connectors (see the following pa-
ragraph: „Test in circuits“). The test principle is a generator
within the R&S®HMO Compact series generates a 50 Hz or
200 Hz (±10 %) sine wave which feeds the series connec-
tion of the test object and a sense resistor. If the test ob-
ject has only a real part such as a resistor, both voltages will
be in phase; the display will be a straight line, more or less
slanted. Is the test object short-circuited, the line will be
vertical (no voltage, current maximum). If the test object is
open-circuited or missing a horizontal line will appear (vol-
tage, but no current). The angle of the line with the horizon-
tal is a measure of the resistance value, allowing for measu-
rementsofresistorsbetweenΩandkΩ.
Capacitors and inductors cause phase shift between vol-
tage and current and hence between the voltages. This will
cause displays of ellipses. The location and the form factor
of the ellipse are determined by the apparent impedance at
50 Hz (resp. 200 Hz). Capacitors can be measured between
µF and mF. An ellipse with its longer axis horizontal indi-
cates a high impedance (small capacitance or large induc-
tance). An ellipse with its longer axis vertical indicates a low
impedance (large capacitance or small inductance). An el-
lipse with its longer axis slanted indicates a relatively large
resistive loss in series with the impedance of the capacitor
or inductor.
With semiconductors the transition from the non-conduc-
If components are tested which are located in circuits or instru-
ments, the circuits resp. instruments must be disconnected rst!
If they are operated from the mains, the mains plug of the test
object has to be pulled out. This ensures that there will be no
loops between the scope and the test object via the safety earth
which might cause false results.
Only discharged capacitors may be tested!
Fig. 9.10: Component tester at short