Hioki MR8827, Instruction Manual

Page: 60 / 436

55
Measurement Configuration
To select the timebase
Refer to the table below when setting the timebase.
For example, to measure a 100 kHz waveform, the maximum display frequency setting range according
to the table is 200 kHz - 800 kHz. If the maximum display frequency is set to 400 kHz, setting the time
axis range to 10 μs/div is recommended.
Timebase Sampling rate (Speed)
Maximum display
frequency
5 µs/div
10 µs/div
20 µs/div
50 µs/div
100 µs/div
200 µs/div
500 µs/div
1 ms/div
2 ms/div
5 ms/div
10 ms/div
20 ms/div
50 ms/div
100 ms/div
200 ms/div
500 ms/div
1 s/div
2 s/div
5 s/div
10 s/div
30 s/div
50 s/div
1 min/div
100 s/div
2 min/div
5 min/div
50 ns (20 MS/s)
100 ns (10 MS/s)
200 ns (5 MS/s)
500 ns (2 MS/s)
1 µs (1 MS/s)
2 µs (500 kS/s)
5 µs (200 kS/s)
10 µs (100 kS/s)
20 µs (50 kS/s)
50 µs (20 kS/s)
100 µs (10 kS/s)
200 µs (5 kS/s)
500 µs (2 kS/s)
1 ms (1 kS/s)
2 ms (500 S/s)
5 ms (200 S/s)
10 ms (100 S/s)
20 ms (50 S/s)
50 ms (20 S/s)
100 ms (10 S/s)
300 ms (3.33 S/s)
500 ms (2 S/s)
600 ms (1.67 S/s)
1 s (1 S/s)
1.2 s (0.83 S/s)
3 s (0.33 S/s)
800 kHz
400 kHz
200 kHz
80 kHz
40 kHz
20 kHz
8 kHz
4 kHz
2 kHz
800 Hz
400 Hz
200 Hz
80 Hz
40 Hz
20 Hz
8 Hz
4 Hz
2 Hz
0.8 Hz
0.4 Hz
0.13 Hz
0.08 Hz
0.04 Hz
0.067 Hz
0.033 Hz
0.013 Hz
S/s = Number of samplings / second
What is the maximum display frequency?
Displaying waveforms by their sampled values with adequate resolution of
characteristics such as sine wave peaks requires a minimum of about 25
samples per waveform period.
Maximum display frequency is determined by the timebase.
What is aliasing (recording of non-existent waveforms)?
If the signal to be measured changes too fast relative to the sampling rate,
beginning at a certain frequency, non-existent slow signal fluctuations are recorded. This phenomena is aliasing.
Actual Input Signal
Sampling Points
Sampling Rate
Measured Waveform
Aliasing occurs when the sampling rate is longer
than half of the input signal period.
With the Memory function, the sampling rate can be significantly affected by the timebase setting, so
care is necessary to avoid aliasing when selecting the timebase. Because the timebase determines the
maximum display frequency, the fastest possible timebase setting should be used.
When the signal can be recorded repeatedly, the auto-ranging function (p. 70) may be used to select
the optimum timebase.
3
Measurement