Omron F3S-B Series Instruction Manual page 17

Using EN 999 Formula
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Safety distance is calculated based on the following equation.
S = K x T + C
S : Safety distance
K : Intrusion speed into the detection zone
T : Total response time for the machine and light curtain
C : Additional distance calculated or defined based on the optical resolution of the light curtain
When safety distance is not provided by European standards for individual machine, the distance can be
calculated using EN 999.
Calculation for intrusion perpendicular to the detection zone
1) 30 mm optical resolution type
Substitute K = 2,000 mm/s and C = 8 (d-14 mm) in equation (1) and calculate as shown below.
S = 2,000 mm/s x ( Tm + Ts ) + 8 ( d - 14 mm )
where:
S = safety distance (mm)
Tm = machine response time (s)
Ts = light curtain response time (s)
d = optical resolution of light curtain (mm)
e.g.:
Tm = 0.05 s, F3S-B122P (Ts = 0.02 s, d = 30 mm)
S = 2,000 mm/s x ( 0.05 s + 0.02 s) + 8 (30 mm-14 mm)
= 268 mm
Use S = 100 mm if the result of equation (2) is 100 mm or less.
Recalculate using the following equation with K = 1,600 mm/s if the result is over 500 mm.
S = 1,600 mm/s x ( Tm + Ts ) + 8 ( d – 14 ) mm
Use S = 500 mm if the result from equation (3) is 500 mm or less.
2) 55 mm and 80 mm optical resolution type
Substitute K =1,600 mm/s and C = 850 mm in equation (1) and calculate as shown below:
S =1,600 mm/s x ( Tm + Ts ) + 850 mm
Note:
1. EN 999 : European Standard. Safety of machinery – The positioning of protective equipment in
respect of approach speeds of parts of the human body
2. The machine response time (Tm) refers to the maximum time from the moment the machine receives
a stop signal to the moment a hazardous part of the machine stops. The machine response time
should be measured and confirmed periodically.
3. The light curtain response time (Ts) refers to the time required for output changing from ON to OFF.
(See Note 1)
(1)
(see Note 2)
(see Note 3)
Safety distance
Hazardous
part
Detection
zone
(2)
(3)
Optical-axis line
Intrusion
direction
F3S-B
17