Catalogs > Safety Products Catalog > Principles, Standards and Implementation > Safety Distance Calculation
Safety Distance Calculation
| Introduction |  |
Formula | |
Directions of Approach | |
Speed Constant | |
Stopping Time | |
Depth Penetration Factor | |
| Reach Through Applications | |
Single or Multiple Beams | |
Distance Calculations | |
Angled Approaches | |
Safety Mats | |
Examples | |
For the normal approach to light curtains, the safety distance calculation for the ISO EN and U.S. CAN are close, but differences do exist. For the normal approach to vertical light curtains where the object sensitivity is a maximum of 40 m, the ISO EN approach requires two steps. First, calculate S using 2000 for the speed constant.
S = 2000 x T + 8 x (d -1 4)
The minimum distance that S can be is 100 mm.
A second step can be used when the distance is greater than 500 mm. Then the value of K can be reduced to 1600. When using K=1600, the minimum value of S is 500 mm.
The U.S. CAN approach uses a one step approach:
Ds = 1600 x T * Dpf
This leads to differences greater than 5% between the standards, when the response time is less than 560 ms. Figure 110 shows the minimum safety distance as a function of the total stopping time for 14 and 30 mm object sensitivity. A combination of both approaches needs to be examined to achieve the worst case scenario for globally designed machines.
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| Figure 110: Safety Distance Comparisons |