Making a danger point safe

Access guarding

Perimeter guarding

Safeguarding an area

Calculating the minimum safety Calculating the minimum safety distance Sdistance S

according to EN 999according to EN 999

Calculating the minimum safety Calculating the minimum safety distance Sdistance S

according to EN 999according to EN 999

S = ?

Calculating the minimum safety distance SCalculating the minimum safety distance Saccording to EN 999according to EN 999

S

S = K x T + C

S = Minimum safety distance in mmK = Approaching speed in mm/msT = Time between interrupting the sensing field and machine standstill in msC = Additional distance depending on resolution in mm

General formula:

Calculating the minimum safety distance SCalculating the minimum safety distance Saccording to EN 999according to EN 999

S

Measures againstover reaching

Measures againstunder reaching

Measures againstreaching from the side

Measures againstreaching from back

Measures may be eitherscrewed on mechanical partsor electrically locked doors.

The sensing field of the AOPDmust be the only access to

the danger point

Calculating the minimum safety distance SCalculating the minimum safety distance Saccording to EN 999according to EN 999

S = (K x T) + C

S = Minimum safety distance in mmK = 2 mm/ms approaching speedT = t1 + t2 + t3 in ms

t1: response time of the AOPD t2: response time of the safety interface

t3: stopping performance of the machineC = 8 x (d - 14) in mmd = resolution of the AOPD (range 14 to 40 mm)

Formula for AOPDs up to 40 mm resolutionand perpendicular approach to the sensing field:

S [mm] = (2 [mm/ms] x (t1+t2+t3) [ms]) + 8 (d - 14) [mm]

S

t1

t2t3

If the result is lower than 100 mm, a minimum distance of 100 mm must be maintained. If theresult is higher than 500 mm, K can be reduced to 1.6 mm/ms. In this case 500 mm is the minimum.

y = “slope of your finger”

Calculating the minimum safety distance SCalculating the minimum safety distance Sfor examplefor example

S [mm] = 2 [mm/ms] x (t1+t2+t3) [ms] + 8 (d - 14) [mm]

Looking at C: C = 8 x (d-14) :

d 14 30 40

C 0 128 208

y = mx + b

y = 8d – 112

movingpart

fixedpart

Sensor Evaluation Unit

19.99

logicunit 85

250

standstillrecognition

tachometer

MAXIMUM SPEED

STOPPING TIME

SLOWING-DOWN PATH

mm

ms

m/s

stop

Uref Uref

pathhold

start

precision potentiometer point of stopping command

output

Principle of a Stopping-Performance Principle of a Stopping-Performance Measurement DeviceMeasurement Device

Resolution of an AOPDResolution of an AOPD

Resolution d = pitch p + lens diameter Ø

d = p + ØChannel

p Ø

Resolution of an AOPDResolution of an AOPD

Resolution d = pitch p + lens diameter Ø

d = p + Ø

pØ

Channel

d < p + Ø

Resolution of an AOPDResolution of an AOPD

Resolution d = pitch p + lens diameter Ø

d = p + Ø

pØ

Channel

d > p + Ø

d

Calculating the minimum safety distance Calculating the minimum safety distance SS

according to EN 999according to EN 999

S

Channel

Channel

Stepping behind protectionusing master and slave units(different resolutions possible).

Note: Calculate both for vertical and horizontal

Calculating the minimum safety distance Calculating the minimum safety distance SS

according to EN 999according to EN 999Direction of approach parallel to the sensing plane of the AOPD

S

Channel

H

d

Relationship between height of the sensing plane above ground and resolution of the AOPD: d = resolution of the AOPDH = height of the AOPD above ground

H = 15 x (dmax - 50) [mm]

dmax = H/15 + 50 [mm]

Minimum safety distance S:

S = K x T + C

K = 1.6 mm/ms

T = (tAOPD + tInterface + tMachine) in ms

C = (1200 - 0.4 H) in mm

H < 1000 mm

H < 300 mm is considered not to allow crawling underneath

(< 850 mm)

Note: @300mm : 70mm resolution, consider RS4-4

Calculating the minimum safety distance Calculating the minimum safety distance SS

according to EN 999according to EN 999Access and perimeter guarding with AOPD

Formula for multiple beam AOPDs:

S = K x T + C K = 1.6 mm/ms approaching speedT = tAOPD + tInterface + tMachine in msC = 850 mm (arm length)

400 mm

900 mm

1100 mm

700 mm

300 mm

Numberof beams

Heights aboveground in mm

4 300, 600, 900, 1200

3 300, 700, 1100

2 400, 900

Calculating the minimum safety distance Calculating the minimum safety distance SS

according to EN 999according to EN 999S = K x T + C

C = 1200 - 0,4 x H in mmCmin = 850 mmSFT = Depth of protection field

Hmin = 15 x (d - 50)

H = Heights of scanning plain d = Resolution of AOPDDRd = 70 mmHmin = 300 mm

Hmax = 1000 mm S HSFT

S = Safety distance in mmK = 1.6 mm/msT = tAOPDDR+tInterface + tMachine in ms

•NOTE: for mobile applications resolutions of 150mm and lessThermal scanners also see dust dirt, hot and cold!