3D TRASAR
5500 - Installation & Operation Manual
521-OM0108.88
Copyright
2009 Nalco Company
Technical Help
(630) 305-CHEM
Glossary-2
Bio-reporter
Bio-reporter is a fluorescent molecule, which is enzymatically changed upon interaction with active,
respiring microbes (both planktonic and sessile). The fluorescence of the bio-reporter and the
product of its interaction with bacteria is monitored continuously by an in-line fluorometer. The rate
of change of the fluorescence with time gives a measure of the microbiological activity in the sys-
tem.
Conductivity measurement
The ability of a sample to conduct heat or electricity. Electrical conductivity is usually expressed in
microsiemens (
u
S.)
Corrosion monitoring
A measurement of the rate at which corrosion is occurring in a system. Corrosion is the deteriora-
tion of metal caused by a reaction with its surrounding environment. Corrosion is measured in units
of mils per year (mpy.)
Failsafe duty, fixed
In the event of alarm conditions, the relay is activated for a period of time equal to a percentage of
a 15-minute period.
Failsafe duty, average or Smart
In the event of alarm conditions, the relay is activated for a period of time equal to the average
operating conditions of that relay for the last 7 days.
Nalco Bio-Index
Nalco Bio-Index is a measure of microbiological control in the system based on the bio-reporter
response. As the Nalco Bio-Index increases the relative microbial control decreases.
Nalco Scale Index
The Nalco Scale Index (NSI) is a calculated variable that compares the current rate of polymer
consumption against the learned average rate of polymer consumption. NSI has a direct correla-
tion to the cooling system stress level. 3D TRASAR Scale Control uses NSI to make setpoint
adjustments in response to both high and low stress conditions.
ORP measurement
Oxidation Reduction Potential. A measure of the oxidation-reduction potential of a sample. ORP is
measured in millivolts (mV.)
