BERTHOLD TECHNOLOGIES Uni-Probe LB 490 - Safety-Technical Data

Uni-Probe LB 490
BERTHOLD TECHNOLOGIES GmbH & Co. KG
1 – 71
Volume 1 9 Functional Safety
1
9.9 Safety-Technical Data
The failure rates of the electronics were determined through
FMEDA according to EC 61508. The calculations are based on the
component failure rates according to SN 29500. All numerical val-
ues refer to an average ambient temperature of +40°C (104°F).
The calculations are further based on the information given in the
chapter “Project Planning”.
(Fit = failure in time = 10
-9
failures per hour)
General data
Single channel architecture 1001
HFT = 0 (Hardware Fault Tolerance)
Two-channel architecture 1002 HFT = 1 (Hardware Fault Tolerance)
λ
sd
783 Fit Safe detected failure
λ
su
174 Fit Safe undetected failure
λ
dd
427 Fit Dangerous detected failure
λ
du
74 Fit Dangerous undetected failure
SFF >96% Safe Failure Fraction
DC
S
82% Safe Diagnostic Coverage
DC
D
85% Dangerous Diagnostic Coverage
Failure reaction time T
Reaction
1.5sec
max. service life of the measuring system for the safety
function
10 years
PFD
avg
T
Proof
= 1 year
T
Proof
= 2 years
T
Proof
= 5 years
<0.032 x 10
-2
<0.064 x 10
-2
<0.160 x 10
-2
Shielding with
source
Tan k
2 Uni-Probes