Knick Stratos Evo A402, User Manual

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According to the “USP” directive (U.S.Pharmacopeia), Section 645 “Water Conductiv-
ity” the conductivity of pharmaceutical waters can be monitored online. To do so, the
conductivity is measured without temperature compensation and is compared with
limit values (see table on next page).
The water is usable when the conductivity is below the USP limit. If the conductivity
values are higher, further test steps must be performed according to the directive.
To increase safety, the USP limit value can be reduced in the device. To do so, a factor
(%) is specified.
Configuration steps
• SNS menu group:
When USP function has been selected, the measuring range is fixed to
00.00.....99.99 μS/cm. Temperature compensation is switched off.
Temperature is monitored.
• Access REL menu group and select USP FUNCT. as limit function.
Relays 1 and 2 can now be used as USP limit contacts.
• Reduced limit contact REL1:
Enter USP factor (reduced USP limit, configurable in the range 10 %...100 %).
Set contact response for relay 1.
Set delay time.
• Limit contact REL2:
REL 2 is permanently set to the USP limit (100%).
Set contact response for relay 2.
Set delay time.
USP Function