Honeywell Krom Schroder PFU 780 - Safety-Specific Characteristic Values

PFU 780 · Edition 02.12l 64
Technical data
9.1 Safety-specific characteristic values
In the case of ionization control, suitable
for Safety Integrity Level
SIL 3
Diagnostic coverage DC 97.9%
Type of subsystem Type B to EN 615082, 7.4.3.1.4
Mode of operation
High demand mode pursuant to
EN 615084, 3.5.12
Mean probability of dangerous failure
PFH
D
1.34 x 10
8
l/h
Mean time to dangerous failure MTTF
d
MTTF
d
= 1 / PFH
D
Safe failure fraction SFF 99.2%
The specified values apply for the combination with
ionization electrode (sensor) and PFU 780 (logic).
Relationship between the Performance Level (PL)
and the Safety Integrity Level (SIL)
PL SIL
a –
b 1
c 1
d 2
e 3
Pursuant to EN ISO 138491:2006, Table 4, the PFU
can be used up to PL e.
Max. service life under operating conditions:
20 years after date of production, plus max. 1/2 year in
storage prior to first use.
For a glossary of terms, see page 68 (Glossary).