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A2 Audio Test & Measurement System
User Manual
GRAPH Printouts
Any graph may be printed out to a connected printer by pressing the <PRINT> button, which
is located on the right hand side of the front panel. Consequently, the complete graph including all curves, the grid and the scaling will be printed.
To select the printer driver, double-click on the <PRINT> key and choose from the menu that
will open. Details about the printers and its selection are given in chapter 7. Printouts.
User Manual
A2 Audio Test & Measurement System
SCOPE Display Mode
The SCOPE mode extends the set of A2/A2 -D tools by offering a simple audio oscilloscope,
that lets the operator analyze the waveform of the input signal(s) in the time domain.
To enter the SCOPE mode, simply push the <SCOPE> button. Consequently, the LC display
will change to the oscilloscope mode and show the input signal(s) vs. the time axis.
Fig. 17 SCOPE Display Example
Fig. 16 Example of a Printed GRAPH Display
The A2/A2-D is not blocked during the print-out. The print process is handled in the background so that any measurement may be performed or continued in the meantime.
Store & Recall Graphs
Sometimes, when using the A2/A2-D, no printer may be available for documentation. Therefore, to allow later printouts of recorded graphs, the A2/A2-D offers four memory locations to
store and recall a complete graphs in each of them, with all the curves and the scaling included. This memory is battery backed-up to allow to disconnect the instrument from mains
power and to return to the office for the print-out. The detailed description on how to store
and recall graphs is described in chapter 6. Sweeps.
On top of the LCD, the generator level and frequency are indicated like in the other display
modes. Below, the waveform(s) are plotted, whe reof the A2/A2 -D automatically determines
the scaling of the Y- (measurement function) and X- (time) axis, i.e. there is no possibility to
set the scaling manually.
• Both resolutions are displayed next to the corresponding axis to allow to read out accurately the amplitude and period. Minimum time resolution is 10µs per division.
• If possible, the auto scaling displays one period of the signal. This ensures, that the operator can qualify the waveform of the input signal without the need to modify the settings.
In the 2 -channel Level mode, the sensitivity of the Y-axis is identical for both channels and
determined by the level of the active (main) channel. Optimized scaling for the alternate
channel can be obtained by making it the active channel (push the <A / B> key). Both in the
2-channel Level and Phase measurement function, the two input signals are shown in a true
phase position.
In the THD+N function, there are also two traces displayed: the smaller one is the distortion
residual after filtering out of the fundamental frequency, while the larger trace shows the unfiltered input signal.
Both traces are synchronized, to enable inspection of where the distortion is occurring. Beware though, due to the phase shift of the notchfilter which removes the fundamental frequency, that the distortion products cannot be exactly synchronized. This effect is worst with
the second harmonic.
In the Noise measurement function, the SCOPE mode is blocked in a way, that the A2/A2-D
automatically switches its display to the METER mode.
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