shenzhen baichuan electronics
(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, and rattle of a loudspeaker. Only one operator is needed.
(5) Measuring distance: 2 to 4 Cm. from the center point. of the dust cover of the pre-measure loudspeaker.
(6) Measuring sensor: Uses ECM.
(7) Dimension ( m / m ) : 85 ( height ) x 205 ( width ) x 280 ( depth ).
(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 a 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 be interfered with 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 selectors 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, and 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 the testing items, to make alternate testing with the loudspeaker’s polarity (WF or M&T).