Kenwood FC-757, Инструкция по эксплуатации, Страница: 31 / 40

order d i g i t s change very q u i c k l y , so t h a t it
becomes d i f f i c u l t to f o l l o w the display v a l -
ues w i t h eyesight.
5 - 6 - 2 Unstable D i s p l a y
The least s i g n i f i c a n t d i g i t ( ± 1 d i g i t ) of a
measurement value m a y have an error a t
d i g i t a l measurement. In t h i s section, errors
other than t h a t w i l l be explained.
If noise or ringing is superimposed on an
input s i g n a l , these unexpected signal waves
m a y w o r k a s pseudo trigger signals to
cause unstable display. Under such operating
conditions, measurement values m a y be out-
put to display a s if they were true.
However, they might be inaccurate due to
the superimposed noise or ringing.
T o solve the above problems, use the input
adjustment functions of t h i s frequency
counter to secure the exact synchronization
t i m i n g s .
In a d d i t i o n , unstable frequency input signal
m a y cause an error. In the period measure-
ment and t i m e interval measurement modes,
pseudo trigger signal m a y cause measure-
ment e r r o r . T h i s measurement error can be
reduced by increasing the number of meas-
urement cycles (by selecting a greater G A T E
t i m e v a l u e ) . T h a t i s , a s m a l l e r resolution
value than the current one should be set
f o r t h a t purpose.
However, if many cycles are handled in the
time interval measurement mode, a count
error per interval m a y occur. The number
of such count e r r o r s w i l l be increased a s
the number of measurement i n t e r v a l s in-
creases. A s a result, a l l the resolution v a l -
ues selected by the G A T E s w i t c h w i l l be
equal and the number of display d i g i t s w i l l
be also increased. T h i s means t h a t the num-
ber of d i g i t s to be possibly affected by
j i t t e r increases. A n y cycle is a reciprocal of
its associated frequency while a n y frequency
is a reciprocal of its associated cycle.
If r e l a t i v e l y low-frequency signal is meas-
ured, the period measurement mode should
be used instead of the frequency measure-
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