TECHNICAL DESCRIPTION AND OPERATING MANUAL ST131 <PIRANHA II> and ST131N
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4.4 WORKING WITH "ACOUSTO-ELECTRIC" CHANNEL.
4.4.1 GETTING STARTED WITH MICROPHONE.
Connect microphone to the «CH2» jack corresponding to the input parameters of the channel
(see section SPECIFICATION). For research in the field of ultrasonic signal frequencies use special
microphones, for example 40BE with microphone preamplifier type 12AL produced by G.R.A.S.
4.4.2 GETTING STARTED WITH SENSOR MAGNETIC FIELD ST131.MF.
Connect the ST131.MF sensor to the connectors «I/O» and "CH2" of the main unit.
4.4.3 WORKING WITH MICROPHONE.
To work with a microphone choose in start MENU the "ACUSTO-ELECTRIC" channel. When
this channel used the screen information will correspond to the FULL RANGE mode (see section 3.1)
Select the desired frequency band, carried out in two ways:
• Rotate the rotary knob. In this case the upper range value limited: 125, 62.5, 31.25, 15.62 and 7.812
KHz.
• Regular transition to the modes FULL RANGE - BAND - DEMODULATION.
In the context of this channel this variant used for the analysis of the ultrasonic signals (above
20 KHz) by down-conversion to the audible range of spectrum.
First way is designed for working in acoustic frequency range, second – in the ultrasound.
To display the signal level using octave filters, press
. Screen information will fit in
Figure 51.
1 Value of the center frequency of the filter.
2 Graphical representation of the signal used with selected
detector (
button).
3 Signal level marker in connection with the peak-hold
detector (PEAKx8).
4 Numerical signal level corresponding to position 2.
Figure. 51
