Table of Contents
Advertisement
order d i g i t s change very quickly, so t h a t
becomes d i f f i c u l t to f o l l o w the display
ues w i t h eyesight.
5 - 6 - 2
Unstable Display
The least significant digit ( ± 1 digit) of a
measurement value may have an error
d i g i t a l measurement. In this 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 as pseudo trigger signals to
cause unstable display. Under such
conditions,
measurement values may be out-
put to display as if they were true.
However, they might be inaccurate due to
the superimposed noise or
T o solve the above problems, use the input
adjustment
functions of this
counter to secure the exact
timings.
In addition,
unstable frequency
may cause an error. In the
ment and t i m e interval measurement modes,
it
v a l -
a t
operating
ringing.
frequency
synchronization
input signal
period measure-
pseudo trigger signal may cause measure-
ment error. T h i s measurement error can be
reduced by increasing the number of meas-
urement cycles (by selecting a greater
time v a l u e ) . T h a t is, a smaller
value than the current one should be set
for t h a t
purpose.
However, if
many cycles are handled in the
time interval
measurement mode, a count
error per interval
may occur. The number
of such count errors w i l l be increased a s
the number of
measurement intervals in-
creases. A s a result, a l l the resolution
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 digits w i l l
be also increased. T h i s means t h a t the num-
ber of digits to be possibly affected
j i t t e r increases. A n y cycle is a reciprocal
its associated frequency while any frequency
is a reciprocal of
its associated cycle.
If relatively
low-frequency signal is meas-
ured, the period measurement mode
be used instead of the frequency measure-
G A T E
resolution
v a l -
by
of
should
31
Advertisement
Table of Contents
