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.

Technical 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.