Hioki LR8450, Instruction Manual

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32
Configuring Input Channels
7
Under [Threshold] , select the level to count.
1 V
 Treats voltages that are greater than or equal to 1.0 V as high level and voltages that
are greater than or equal to 0 V but less than 0.5 V as low level.
4 V Treats voltages that are greater than or equal to 4.0 V as high level and voltages that
are greater than or equal to 0 V but less than 1.5 V as low level.
8
Under [Filter] , select whether to use the chatter prevention filter.
Set to [ON] to prevent false counting due to chatter in mechanical contact (relay) output.
OFF

, ON
9
Under [Smoothing] , enter the smoothing processing time (when [Range] is set to [r/min] ).
1 s

to 60 s
Principal of rotational speed measurement
Under the following conditions, the integration pulse count is internally updated at a data refresh
interval of 10 ms:
• When the range is [r/s]
• When the range is [r/min] and smoothing is set to [1 s]
The rotational speed at time
t
[s] is calculated by dividing the pulse count from (
t
- 1) to
t
[s] by the
number of pulses per revolution.
r
(r/s) =
Integrated pulse count at t [s] − integrated pulse count at ( t − 1) [s]
Number of pulses per revolution
r/s: Rotational speed per second
r/min: Rotational speed per minute (with smoothing set to [1 s] )
r (r/min) =
I
ntegrated pulse count at
t
[s] − integrated pulse count at (
t
− 1) [s]
Number of pulses per revolution
× 60
Example: Number of pulses per revolution = 4
Integrated pulse count at 1 s = P1 = 1000 c
Integrated pulse count at 2 s = P2 = 2000 c
The rotation speed at
t
= 2 s (
r
t =2
) can be calculated as follows:
r
t =2
= (2000 - 1000) / 4 = 250 r/s
When the range is set to [r/min ] and smoothing is set to t
0
[s], the integrated pulse count is
internally updated at a data refresh rate of 50 ms.
The rotational speed at time t [s] is calculated by dividing the pulse count from ( t - t
0
) to t [s] by the
number of pulses per revolution and multiplying the result by 60.
r
(r/min) =
I ntegrated pulse count at t [s] − integrated pulse count at ( t − t
0
) [s]
Number of pulses per revolution
×
60
t
0