Hioki LR8431, Instruction Manual, Page: 63 / 204

3.4 Setting Configuration 2 – Input Channel Settings
55
3
3
Chapt
er
3 Sett
ing be
fore M
easure
ment
Revolution Measurement Theory
Pulse count is measured using the Memory HiLogger’s

internal 10 ms sampling interval.
The revolution rate ( r ) per second during time t
s
is obtained
by dividing the number of pulses from ( t -1) to t
s
by the num-
ber of pulses per revolution.
Example: Pulses per revolution = 4
When the number of pulses counted in one second is
P
100
= 1000 c,
and the number of pulses counted in two seconds is P
200
= 2000 c,
then the revolution rate (rps) at
t =2s ( r
t=2
) can be obtained.
When time t
s
is less than one second
The pulse count at ( t –1)
s
(whole seconds) cannot measured, so 100 times the pulse count
between ( t -0.01)
s
and t
s
serves and the pulse count for one second to obtain the revolution
rate.
As a result, revolution measurements when
t is less than one second are scattered.
0 10 ms 20 ms 1 s 2 s
Pulse Count
P200 P100 P2 P1 0
Pulses per revolution
Pulse count at t
s
minus pulse count at ( t -1)
s
r [rps] =
(rps: Revolutions per second)
r
t=2
=
4
2000

1000
= 250 [rps]
Pulses per revolution
Pulse count at t
s
minus pulse count at ( t -0.01)
s
r [rps] = x 100