Stratos Multi E401N
81
5.9.5 USP Function
Monitoring Ultrapure Water in the Pharmaceutical Industry
The conductivity of ultrapure water in the pharmaceutical industry can be monitored online in
accordance with the guideline “USP” (U.S. Pharmacopeia), Annex 5, Section 645 “Water Conductivity”.
The conductivity is measured without temperature compensation and is compared with limits.
The water is usable without any further testing when the conductivity is below the USP limit.
Configuring the USP Function
The USP value can be configured as a process variable USP% for output (display, current output, limit,
measurement recorder)
Settings can be changed in the
USP
submenu:
Parameter Setting
[I] [II] … Cond(I)
USP
Reduced limit
: The USP limit can be reduced down to 10 %.
Monitoring
: Select whether and how an exceeded limit is to be displayed.
Off
No message, but the parameter is still shown in the Diagnostics menu.
Failure
A failure message is shown in off-limit conditions; the corresponding NAMUR icon
is displayed.
Mainte-
nance
A maintenance required message is shown in off-limit conditions; the corresponding NAMUR icon
is displayed.
USP Function: Specifying a Relay Contact
The USP function can also be assigned to a relay contact:
Parameter Setting
Inputs and Outputs
Relay Contacts
Contact K…
Display of the USP Function in the Diagnostics Menu
Diagnostics
[I] [II] … Cond(I)
USP Function
Display of the USP limit, the reduced limit, and conductivity.