10
This distance is the minimum separation
distance. All possible directions of
approach must be considered. The
minimum separation distance, S, can be
calculated using the following formula:
S = (1600 x T) + 1200
The overall system response time, T,
should be measured several times and the
highest value recorded, plus a suitable
allowance for brake deterioration, should
be used in the calculation of the
minimum separation distance.
1.6.1.3 USE AS PRESENCE SENSING
DEVICE
When the system is used solely as a
presence sensing device it is normally
used as a secondary guarding device in
conjunction with a separate primary
guarding device. The primary guarding
device would normally, as a minimum,
operate as a trip device. The position of
the trip device should be determined
according
to
the
manufacturers
instructions. The primary guarding device
could be an interlocking fence, photo
-
electric curtain or similar device.
In this case it is necessary to ensure that
the dangerous area, between the primary
guarding device and the machine is
completely covered by the active area of
the sensor(s), such that it is impossible
for a person to stand between the primary
guarding device and the dangerous parts
of the machine without standing on the
active area of the mat(s).
1.6.1.4 USE AS A TRIP DEVICE
When the system is used solely as a trip
device the minimum separation distance,
i.e. the distance from the front edge of the
active zone of the mat to the nearest
dangerous parts should be calculated as
described in section 1.6.1.2.
The minimum width of the active zone of
the mat should be 750 mm (i.e 810 mm
overall) to ensure that an operator cannot
inadvertently step over the mat into the
dangerous area without actuating the mat.
See Figure 6.
MACHINE
7
5
0
m
m
M
IN
M
IN
S
E
P
A
R
A
T
IO
N
D
IS
T
A
N
C
E
(S
)
Figure 6
—
Mat solely used as a trip device
