38
Analysis
individual components. If circuits of the same type have to
be tested often (service), comparisons with intact circuits
may help again. This is also quickly done because the intact
circuit has not to be functional, also it should not be ener-
gized. Just probe the various test points with the cables of
the component tester of the unit under test and the intact
unit and compare the screen displays. Sometimes the unit
under test may already contain an intact portion of the
same type, this ist e.g. the case with stereo circuits, push-
pull circuits or symmetrical bridge circuits. In cases of doubt
one side of the dubious component can be unsoldered.
9 .6 Digital Voltmeter
The digital voltmeter completely captures input data with
the selected vertical sensitivity and the basic accuracy of
the ADC. The digital voltmeter is independent from the
capture settings and the post processing of the transfor-
mer values. Determine the values by means of the measu-
rement interval to ensure the defined frequency range of
20 Hz to 100 kHz. The measurement interval of the digital
voltmeter is not corresponding to the acquisition time
interval. Therefore, the measurement values of the digital
voltmeter can not be the same like the measurement va-
lues of the AUTO MEASURE values.
The analysis function DIG. VOLTMETER can be activated by
using the UTIL menu in the VERTICAL control panel. The
Fig. 9.11: Excamples of Component test
digital voltmeter includes a 3-digit voltage display as 7-seg-
ment display with the use of the analog channels. Four freely
configurable measuring displays are possible where two
measurement value displays for channel 1 (CH1) and two
measurement value displays for channel 2 (CH2) are availa-
ble. For each channel, the measurement displays are divided
into in a primary measurement location (soft menu key Chan-
nel 1 / Channel 2) and a secondary measurement location
(soft menu key SECONDARY). The primary measurement
display will be shown in a large font, and the secondary mea-
surement display in a small font. All measurement displays
can be configured separately.
The following primary and secondary measurement displays
are available:
❙
OFF:
Measurement display deactivated
❙
DC:
Mean
❙
DC RMS:
RMS
❙
AC RMS:
Standard Deviation
❙
CREST FACTOR:
Crest factor (|X|max/XRMS)
❙
PEAK PEAK:
Maximum-Minimum
❙
PEAK +:
Maximum
❙
PEAK -:
Minimum
Use the soft menu key POSITION to change the display
position of the digital voltmeter on the screen. When the
XY mode is activated, the display position of the digital volt-
meter is predefined and cannot be modified. Use the soft
menu key VOLTMETER OFF to deactivate the digital voltme-
ter function and to close the menu.
Fig. 9.12: Digital Voltmeter.
