Kenwood FC-758 Instruction Manual page 25

Sn the following paragraphs, the relationship
between measurement modes and measurement
delays w i l l be discussed.
1) Frequency measurement mode
The relationship between the operational modes,
resolution values and measurement periods in the
frequency mode is shown below :
Measurement
Resolution
Mode
value setting
100 Hz
kHz kHz
0.1 Hz
100 Hz
MHz MHz
10 kHz
Prescale input
1 kHz
( C H A N N E L B
100 Hz
INPUT J U C K ) INPUT J U C K )
A s the above table shows, the gate time w i l l be
short if a low resolution value is selected. T h i s
w i l l be helpful in f i n e - a d j u s t i n g an oscillator,
which requires quick update.
The update interval w i l l be long if a high resolution
value is selected.
1 1 Gate Time Gate Time
0. 01s
10 Hz 0. Is
1 Hz I s
10 s
1 kHz
0. 01s
0. Is
10 Hz I s
1 Hz 10 s
0. 027s
0. 27s
2. 7s
10 Hz 27s
2) Period measurement mode
The period measurement mode processes the speci-
fied number of cycles and then outputs the aver-
age cycle time. The desired number of cycles can
be specified by using the G A T E s w i t c h .
The relationship between the number of cycles and
the G A T E s w i t c h is shown the table below.
Resolution
value setting
0.1 /is
0.01 ps
0.001
ps
0.0001/is
3) Inter-measurement interval
T h i s interval is fixed a t 200 milliseconds in a l l
modes expect event input t o t a l count measurement
and prescale measurement modes.
In prescale measurement mode it is 540ms, and
in event input t o t a l count measurement mode,
counting is continuous.
T h i s fixed interval is independent of gate time,
number of cycles, or input frequency.
No. of cycles
measured
1
10
100
1000
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