Application of conductivity. The water contains

contaminants, largely ionic, that if not removed will cause

scaling and corrosion in plant equipment, particularly in heat

exchangers, cooling towers, and boilers.

(a)  

is also used to monitor the build up of dissolved

ionic solids in evaporative cooling water systems and in boilers.

(a)  

The choice of which to use depends

on the amount of conductivity, the corrosiveness of the liquid,

and the amount of suspended solids.

(a)  

the (a)  

method is better when the conductivity is high, the liquid is

corrosive, or suspended solids are present.

consist of two metal

electrodes, usually stainless steel or titanium, in contact with the

electrolyte solution,

(a)  

The electric field causes the ions to move

back and forth producing a current. Because the charge carriers are

ions, the current is called an

(a)  

measures the

current and uses Ohm’s law to calculate the resistance of the solution

(resistance = voltage/current).

(a)  

The conductance of the solution is the

(a)  

In the ____ _________ ___________, the analyzer injects an

alternating current through the outer electrodes and measures

the voltage across the inner electrodes.

(a)  

calculates

the conductance of the electrolyte solution from the current

and voltage.

(a)  

Inductive conductivity is sometimes called

(a)  

consists of two wire-wound metal

toroids encased in a corrosion-resistant plastic body. One toroid is the

drive coil, the other is the receive coil. The sensor is

(a)  

measures the degree of acidity or

basicity of a solution.

(a)  

are materials that are specifically designed to

change color when exposed to different pH values. The color of a

wetted sample paper is matched to a color on a color chart to infer a

pH value.

(a)  

This device uses a vial filled with an appropriate

volume of sample to which a reagent is added. As the reagent is

added, a color change takes place. The color of this solution is

then compared to a color wheel or spectral standard to

interpolate the pH value.

(a)  

is a common laboratory

application of this principle Colorimetric pH measurement, where a color changing chemicalsubstance infused on a paper strip changes color when dipped

in the solution.

(a)  

is a common pH test method used for manual

laboratory analyses, but it is not well suited to continuous process

measurement.

(a)  

By far the most common pH measurement method in

use is

(a)  

electrochemical pH measurement is based

on the _, which describes the electrical potential

generated by a difference in ionic concentration between two different

solutions separated by an ion-permeable membrane.

(a)