Data Harvest EASYSENSE Q Advanced Manual page 39

Acceleration at A
Double interrupt card
Time taken
for velocity
to change
Picket fence
When a picket fence is used to measure Acceleration at A, the measurements shown are for
instantaneous acceleration i.e. it took this amount of time to travel this distance and the acceleration
was.
To improve the accuracy of readings, an increment is automatically applied to a picket fence with a
pitch length of less than 60 mm. This will mean that there are fewer readings than number of pitches
on a fence.
Note: It is envisaged that when a picket fence with a pitch length of 10 mm is used that it will be used on a buggy type
investigations (which produce slower times than dropping thorough light gates), the times are therefore averaged over
less pitches.
Raw Data
t
0
3
V
(l)
1
2
t
2
t
0
1
V
(l)
1
1
t
0
Instantaneous Acceleration is calculated using the change
in Velocity of 2 pitches divided by the time taken for the
t
4
velocity to change.
t
3
V – V
1
t
2
t + t – t
2 0
2
t
1
t
0
Average acceleration can be measured using a
single light gate with a double interrupt card.
Acceleration is calculated using the length of the
segments on the double interrupt card.
Acceleration = Change in Velocity =
V Length of segment - V
2
Time (t
3
2
+ t
3 1
2
39
Time taken
Length of segment
1
– t ) Time (t
2
Time taken
The blue button
can be used to scroll
through and examine
the readings already
taken
– t )
0 1
The blue button
can be used to scroll
through and examine
the readings already
taken