DIGITAL HIGH SPEED Fo METER
MODEL – 7117C
Ⅰ. Function:
Model – 7117C has the following two main functions:
A. Model-7117C can measure the Fo value of a loudspeaker fully automatically, no need of
manual adjustment of the instrument. The correct Fo value of a loudspeaker is being
displayed on the〝 DISPLAY PANEL〞( 14 ) in just 1 to 1.5 seconds. It has many
advantages than by using a voltmeter with a needle indicator for measuring the Fo value
of a loudspeaker:
( a ) Easy to read; ( b ) No visual error; ( c ) High accuracy.
B. Model-7117C can be used in a production line: , high speed judging if Fo value of every
loudspeaker is within the qualified range, Judging speed is as fast as in just 0.3 to 0.7
second, the “ PASS / FAIL Test” functions will be indicated instantly.
Ⅱ. Specification:
A. Display: Displayed in 3 digits.
B. Accuracy: Fo readout error less than ± ( 1% + 1Hz )
C. Measuring Range: 4 ranges from 16Hz to 3KHz,
( a ) 16Hz - 80Hz ; ( b ) 54Hz - 270Hz.
( c ) 180Hz - 900Hz ; ( d ) 600Hz - 3KHz.
D. Fo measuring voltage added on the pre-measure loudspeaker: 1V r.m.s. ± 10%
( complies with EIA standard ).
E. Can test the impedance of an under-testing loudspeaker: Divided into two ranges, which
are (1) 3Ω to 18Ω; (2) 19Ωto 100Ω.
F. Measuring Speed: 〝 Fo Readout 〞in 1 to 1.5 seconds.
〝PASS / FAIL Test〞in 0.3 to 0.7 second.
G. Limit Setting: Both the upper & lower limits of a loudspeaker can be preset independently
from 16Hz to 3KHz, and have no interference with each other.
H. Limitation in usage: Model-7117C can not be used to measure the Fo value of an air
suspension loudspeaker, including those loudspeakers which are air tight frame, since
their Q.o. values are too low to measure.
