Loudspeaker Polarity Tester Model-139B
Even in a very noisy environment, Model-139B still has the ability to determine quickly and
precisely the positive and negative polarity of a loudspeaker、headphone、receiver and every
single unit in a loudspeaker system. Model-139B also includes 3 sets of external input terminal
and selector which can be used to combine with other instruments, in order to measure the other
features of a loudspeaker simultaneously. It is quite suitable for 100% Q.C. testing for
loudspeakers in production line.
Ⅰ. Characteristic
(1) Model-139B can determine at once the positive & negative polarity of a loudspeaker,
receiver, headphone and every single unit in a loudspeaker system.
(2) Model-139B uses both the "positive" & "negative" polarity indicators, to measure instantly
the positive & negative polarity of a loudspeaker, besides, to avoid visual error that causes
the wrong determination of polarity, Model-139B is designed with the supplement of a
beeper, which when buzzing, indicates the positive polarity.
(3) Model-139B can't not be interfered by the background noise, even in a noisy production
line, Model-139B still can determine quickly & precisely the polarity of a speaker.
(4) Model-139B also includes 3 sets of external input terminal and selector which can be used
to combine with other instruments, in order to measure the other features of a loudspeaker,
for example :
(a) Model-139B can combine with an Impedance Meter / Freq. meter ( Model-152A ), to
measure the impedance of a loudspeaker.
(b) Model-139B can combine with a Digital High Speed Fo Meter ( Model-7117C ), to
measure the Fo value of a loudspeaker.
(c) Model-139B can combine externally with an Audio Sweeper(Model-7116C), to test the
buzz, rattle of a loudspeaker, it needs only one person to operate, its quite speedy &
convenient to operate. Users may use a foot switch to control the selection of either one
set of testing item, to make alternate testing with loudspeaker's polarity (WF or M&T).
Specification
(1) Pulse measuring method.
(2) Polarity indicator :
(a) Green indicator : Positive polarity with beep sound.
(b) Red indicator : Negative polarity with no sound at all.
(3) Five touch switches :
(a) WF range : Suitable for measuring the polarity of woofer.
(b) M & T range : Suitable for measuring the polarity of midrange and tweeter.
(c) EXT.1 to EXT.3 : Used to select the instrument connected to the external input
terminal.
(4) Model-139B can be connected with Model-7116C, to measure the buzz, rattle of a
loudspeaker. Only one operator is needed.
(5) Measuring distance : 2 to 4 Cm. from the center point. of dust cover of the pre-measure
loudspeaker.
(6) Measuring sensor : Uses ECM.
(7) Dimension ( m / m ) : 85 ( height ) x 205 ( width ) x 280 ( depth ).
(8) Weight : 2.3 Kg.
