IM 12D08N05-01E
5-14
<5. MENU STRUCTURE COMMISSIONING>
5.9 Simulate
The contact can be switched on/off or a percentage of output can be simulated. On/Off
enables the user to manually switch a contact on or off. The percentage is an analogue
value and represents the on time per period.
The Duty cycle Period time (see figure 5.4) is used as a period for percentage simulation.
Note that the (simulated) settings of the contacts become visible in measuring mode
and after HOLD has ended c.q. has been overruled. A warning is activated in case of a
simulated output contact.
5.10 Water for Injection Monitoring (USP 645 and
EU 0169)
l
Setting up SC450G for WFI monitoring
1. A function “USP limit exceeded” is defined as an error code on sec. 5-12, Errors
2/3. This can be set to off/warn/fail according to your requirement. This function
can be modified by the function “USP safety margin” in %. This is a percentage of
the WFI conductivity value at that temperature that serves as safety margin. This is
independent of what is being measured. The display shows this error when the water
quality exceeds the WFI conductivity limits as set in stage 1.
2. We have introduced uncompensated conductivity in the DISPLAY menu. In the LCD
display the user can read the temperature and the raw conductivity to compare his
water quality with the WFI table.
3. We have added a USP function to the contact allocation. The contact output S1 can
be selected as USP alarm if the function “USP limit exceeded” has been selected.
The contact closes when the USP limit is reached.
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
μS/cm
USP
Safety
Margin
25
50
75
100
˚C
Figure 5.6 USP Safety Margin
Limit of uncompensated conductivity as function of temperature as defined for WFI. USP
safety margin set as 20 % will close the contact at 80 % of the conductivity value at all
temperatures.
For example, if the temperature is 64 ºC. and the safety margin is adjusted for 20%, then
the contact closes at 0.8 x 2.2 μS/cm. = 1.76 μS/cm. (2.2 μS/cm is the WFI limit at 64ºC).
In resistivity mode the contact will close at an uncompensated resistivity of 1/1.76 μS/cm. =
0.568 Mohm.
Recommended Commissioning settings when monitoring WFI in a > 80 ºC WFI installation.
