Wintriss Shadow VI, User Manual

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Shadow VI User Manual 1107200
Installation and Checkout Chapter 2 page 23
(The stopping time for older brakes will be longer due to wear. Therefore, you add less time
for older brakes. This way, the brake monitor setting comes out approximately the same
whether the brakes are new or old).
Dpf is the depth penetration factor, and equals 3.3" (8.4 cm). This is a measure of how far an
object, like an operator's hand, can move through the light curtain before the light curtain
reacts.
Dpf is related to the object sensitivity.
Object sensitivity is the smallest diameter object that Shadow VI will detect anywhere in its
field. Object sensitivity
(S) for Shadow VI is 1.25" (3.2 cm), with beam centers of
3/4
" (1.9
cm). An object smaller than 1
1/4
" diameter could pass through the light field if it traveled in
a path directly between the light beams. European standards discuss object sensitivity as it
relates to the type of detection provided. For example, object sensitivity of less than 0.6”
(1.5 cm) provides finger detection. Object sensitivities greater than 0.6” and up to 1.3” (~3.3
cm) offer hand detection. Object sensitivities within the hand detection range are equally
effective.
For Shadow VI with one beam blanked, refer to the section "Blanking windows affect safety
distance" further on in this chapter.
An example of calculating the safety distance using ANSI formula
Here is an example of how to use the formula to calculate safety distance ( Ds ): First take a look
again at the formula we must use:
Ds = K x (Ts + Tc + Tr + Tbm) + Dpf
Let's use these numbers for our variables in the formula:
K (hand speed constant) = 63 inches per second (set by OSHA)
Ts + Tc = 0.190 sec.
We include Ts and Tc together because many stop time measuring devices measure stopping time of
the press control as well as the stopping time of the clutch/brake mechanism.
Tr = .040 sec. (response time of Shadow VI)
Tbm = 0.228 sec. (brake monitor setting) – 0.190 sec = .038 sec.
Dpf = 3.3
Now let's put our numbers into the formula:
Ds = K x (Ts + Tc + Tr + Tbm) + Dpf
Ds = 63 x (0.190 + .040 + .038) + 3.3
Ds = (63 x .268) + 3.3
Ds = 16.88 + 3.30
Ds = 20.18"
The distance the light curtain must be mounted from the pinch point in our example is 20.18". When
using the formula, be sure to do all calculations in this order:
(1) Add Ts + Tc + Tr + Tbm first.
(2) Multiply the result by 63.
(3) Add this result to Dpf. This is Ds.
If you do not follow this order, your safety distance calculation will be incorrect.