72-910-16 Rev. N
Page 38 of 43
13. GLOSSARY
Alarm Relay
– an electric circuit when triggered by a predetermined signal will activate an externally connected
alarm
Analog
– a continuous signal (4-20mA) that can be used to represent a physical variable, e.g., conductivity
Biocide
– an agent used to control the growth of algae and other organic substances
Bleed
– to release water from the system, used to control conductivity
Bleed Valve
– the valve that opens or closes to release water from the system activated by a signal from the
Controller
Buffer Solution
– a solution with a specific pH value used as a control in calibrating probes.
Calibration
– a procedure to match values “read” by probes to actual real world values
Chattering
– a situation that occurs when relay controlled device repeatedly turns off and on
Chemical Feed Pump
– a relay or proportionally controlled pump that disperses chemical into the system (e.g.,
PULSAtron)
Chemical Metering Pump
– see Chemical Feed Pump
Conductivity
– the ability of a substance to conduct electrical current, concentrations of dissolved and suspended
solids in water directly determine the conductivity of the water
Conduit
– tubing through which wire is run
Configure
– procedure to setup basic functions of the controller, i.e., date, time, set point control, etc.
Contacting head water meter
– a water meter that outputs a dry contact signal every time it pulses
Contrast
–
difference in brightness between adjacent objects, e.g., darkness of text in screen display verses
background
Cooling Tower
– a structure of various sizes that allows heat to radiate away from the system water
Cursor
– See prompt
Cycle Timer
– a timing device that can be preset to turn off and on at specific intervals
Differential
– also referred to as dead band or hysteresis, this is a range or offset applied to a set point value (see
chattering)
Dry Contact
– relay contacts without power
Electrodes
– or probes, the metal protrusions that measure conductivity in the conductivity probe assembly
Float Switch
– a mechanical switch that provides an electrical contact when the water level rises to a
predetermined height
Flow
– refers to the movement of water through the system
Flow Assembly
– an option, which attaches to the controller and incorporates a flow switch, probe/probe ports,
and sample valve
Hall Effect Water Meter
– Solid state flow detection device
Heat Exchanger
– a mechanical device that facilitates the transfer of heat between two mediums
High Current
– 20 mA signal
Hi Lo Alarm
– a function of the controller that signals the user when conditions exceed a predetermined high or
low value
HOA
– abbreviation for Hands-Off-Auto relay control
Inhibitor
– a chemical or compound used to aid the control of corrosion or scaling in the cooling tower system
Inhibitor Feed
– term referring to the disbursement of inhibitor in to the system
Inhibitor Timer
– a function of the controller that regulates the amount of time inhibitor is introduced to the
system
Initialization
– a procedure to reset the controller to original factory conditions
Inorganic Scale Deposits
– undesirable precipitate formations within the cooling tower system
