Technical Manual WD 230 and WD 250
Rev. 1.8 PF
Page 27
73018_E rev 1 8-Technical Manual.doc
During programming, both media
M6 and M9 must always appear in the same pro-
gram.
Should M9 not appear in the same program, the DI water will be sent by way of
the overflow into the drain.
4.5.9 F0 function step inactive
A step may be added or removed. E.g. 2 rinsing steps may be programmed, customer
may elect to deactivate one rinsing step. The second step will subsequently be shifted
from F4 to F0. The SW will jump this step, in spite of the fact that these parameters are
set.
4.5.10 F1 – F5, F8 and F 9, FD, FE function display
These are pure indicator functions. The dwell time is et to 0.
M8 should always be applied together with FD and M4/9 together with F9. As a rule, final
rinse is used instead of clean rinse.
4.5.11 F6 and F 7 thermal disinfection or chemical disinfection
In these functions, the dwell time is set to 1 in addition to the display function.
4.5.12 FA Thermal disinfecting
A
O
= 3000
Selection of Ao values in practical application
The norm EN ISO 15883-1 defines disinfection as follows: «Reduction of living micro or-
ganisms on a product to a predetermined level that is appropriate for the subsequent
application of the product». Reduction factors of 5 or sometimes 4 log magnitudes are
required of chemical disinfecting additives, depending on types of germs (Virus,
prEN14476). Which titer reduction is appropriate for a thermal disinfecting process?
EN ISO 15883 defines two different applications with one associated Ao value for each.
According to this, containers for human excrements (part 3 of the norm) must be disin-
fected with a minimum Ao=3D 60, surgical instruments etc. (part 2) with minimum
Ao=3D 600.
In addition, according to the norm, an RDT must be in a position to carry out a disinfec-
tion with Ao=3D 3000, however, an appropriate application is not defined.
The Robert Koch Institute in Germany recommends an Ao value of 3000 for all critical
medical products. Medical products that are contaminated by heat resistant viruses such
as Hepatitis B – Viruses, must be disinfected with an Ao value of 3000.
All semi-critical instruments, i.e. those that are thermally disinfected but will not go
through a subsequent sterilization process should be disinfected with A
O
= 3000.
According to definition CEN/TC102 WG8 N305 EN ISO 15883-1 Annex A
A
O
concept; comparative lethality of mister heat processes
A reduction of the exposure time for decontamination process can be achieved by using
the function FA. The control continually measure and add the prevailing heat quantities
according to the Equation
A
0
=
∑
10 (T-80) /Z
∆
t
(Z = 10,
∆
t
= 10 Seconds above 65°C)
already during the heat up phase and finish the phase thermal disinfections immediately
on reaching the requisite A
O
= 3000 / 600 value.
Example 1
P1S4_093°00M-093°01M
FA
M4_D1=0.0L-D3=2.6L
After reaching in the first phase the value A
O
= 3000 at 93°C, the second phase of dos-
ing 3 for 1 Min 93°C will be processed.
