2-35
IM DL850E-01EN
When using the offset function and making measurements
by expanding near 100 kHz
Original waveform
When using the smoothing filter
Filter order: 50 ms
Value/div:
200 Hz/div
Upper display
limit: 101 kHz
Lower display
limit: 99 kHz
The accuracy
improves when
the smoothing
filter is used.
• Pulse Averaging (PulseAverage)
The input pulses are divided into groups of a specified number (1 to 4096 pulses) and measured. Pulse
averaging has the following characteristics.
• Enables you to eliminate the effects of missing pulses and inconsistent pulse intervals (inconsistencies in
the frequency or period waveform) on measurement.
• Even if you use pulse averaging, the measured results are displayed as per-pulse values, so there is no
need to reperform scaling.
• Pulse averaging can be used in measurements of frequencies, revolutions, periods, power supply
frequencies, pulse integration, and velocities.
f
1
f
2
f
3
N = 11
When pulse averaging is used
When pulse averaging is not used
Deceleration and Stop Prediction
The 701280 (FREQ) automatically performs internal computation and displays waveforms by predicting the
deceleration curve and stop point even when the input pulse is suddenly cut off. This function enables the
measurement of waveforms of deceleration behavior that are close to the actual physical phenomenon in
applications in which the deceleration behavior of an object that has inertia is measured, such as in automobile
brake tests.
• Deceleration Prediction (Deceleration Prediction)
The deceleration curve is computed according to the following equation using the elapsed time after the pulse
input stops (Δt).
Frequency (f) = 1/elapsed time (Δt)
The deceleration prediction starts after the pulse input stops and a pulse period (T) of the pulse one period
before the pulse input stopped elapses.
• Stop Prediction (Stop Prediction)
The point at a specified time after the pulse input stops is considered a stop point, and the frequency is set to 0.
The time from the point when the pulse input stops to the point when the DL850E/DL850EV determines that
the object has stopped can be set to 1.5, 2, 3, ..., 9, or 10 times (10 options) the pulse period (T) of the pulse
one period before the pulse input stopped.
2 Vertical Axis