Manual

Measurement Functions
3-11
3.63.6
3.63.6
3.6
PolarityPolarity
PolarityPolarity
Polarity
In combination with the Minirator MR1, the Minilyzer provides a powerful
feature to detect the polarity of the signal at the output of a device.
This function may be applied to check for example the
• polarity of loudspeakers
• condition of balanced cables
In order to execute a polarity test, proceed as follows:
• Connect the MR1 to the input connector of the device.
• Activate the PolTest-signal of MR1 and adjust the level.
• Enter the polarity measurement function of ML1.
• Select the input source
- MIC(INT), the internal microphone or
- XLR/RCA, input-connectors
by placing the cursor to the IN: entry field, press enter, select with
the arrow keys and confirm your setting with enter again.
NOTES • Place the internal microphone close to the speaker
to be tested in order to evaluate its polarity.
• To ensure reliable readings reduce the level of low
frequencies, e.g. bass or subwoofer.
• The polarity test may be carried out with the external
microphone MiniSPL (select XLR/RCA as input source).
An overrange indicator appears for levels exceeding the instruments
operating range. In this case increase the distance between microphone
and loudspeaker or reduce the volume.
Fig 18 Polarity Test Screen
The following examples explain the correlation between the reference
level and the reference indicator.
Example 1
Given vu-meter reference level set to +4 dBu
Input signal = steady-state sine wave of +4 dBu
Result vu meter level = 0 (reference indicator level)
Example 2
Given vu-meter reference level set to 0 dBu
Input signal = steady-state sine wave of +4 dBu
Result vu-meter level = +4 (+4 dB above reference indicator)
Example 3
Given PPM Nordic standard, reference level set to +12 dBu
Input signal = steady-state sine wave of +6 dBu
Result PPM level = TST (-6 dBu below reference indicator level)
b.b.
b.b.
b.
Peak HoldPeak Hold
Peak HoldPeak Hold
Peak Hold
There are two different types of peak hold on the vu+PPM screen:
• Two numerical peak hold indications, located above the right hand
end of the vu and the PPM bargraph.
The numerical peak hold indicates the all-time max. input level
since the vu+PPM mode has been entered. It may be reset by
placing the cursor to it and pressing the return key.
To reset the two numerical peak-hold simultaneously, simply re-
enter the vu+PPM mode.
• Two graphical peak hold indications, represented by a vertical line
in each bargraph. The graphical peak hold display has a decay
time of approximately one second.
c.c.
c.c.
c.
Integration TimeIntegration Time
Integration TimeIntegration Time
Integration Time
The PPM display provides an additional entry field to select the attack
and release times between NRM (normal) and FAST.
• In the NRM mode, the value of the integration time is given by
the corresponding standard (Type I: 5 ms; Type IIA: 10 ms; Nordic:
5 ms)
• In the FAST mode, the integration time is 1 ms for all standards.
Measurement Functions
3-10