Endress+Hauser Liquiline System CA80HA, Operating Instructions Manual

Page: 145 / 214

Liquiline System CA80HA Operation
Hauser 145
Calculated pH value
The pH value can be calculated from the measured values of two conductivity sensors under
certain conditions. Areas of application include power stations, steam generators and boiler
feedwater.
Menu/Setup/Additional functions/Mathematical functions/MF1 to 8/Mode = pH calculation from conductivity
Function Options Info
Calculation Selection
• Off
• On
Factory setting
Off
On/off switch for the function
Method Selection
• NaOH
• NH3
• LiOH
Factory setting
NaOH
The calculation is performed on the basis of
Guideline VGB
‐
R
‐
450L of the Technical
Association of Large Power Plant Operators
(Verband der Großkesselbetreiber, (VGB)).
NaOH
pH = 11 + log {(κ
v
- 1/3 κ
h
)/273}
NH3
pH = 11 + log {(κ
v
- 1/3 κ
h
)/243}
LiOH
pH = 11 + log {(κ
v
- 1/3 κ
h
)/228}
κ
v
... Inlet ... direct conductivity
κ
h
... Outlet ... acid conductivity
Inlet The options depend on the
sensors connected Inlet
Sensor upstream from the cation exchanger,
"direct conductivity"
Outlet
Sensor downstream from the cation exchanger,
"acid conductivity"
Selection of the measured value is obsolete as it
must always be
Conductivity .
Measured value
Outlet
Measured value
Calculated pH Read only View this value in a user-defined measuring
screen or output the value via the current
output.
Mathematical function
assignment view
Overview of the configured functions
Formula (optional, with activation code)
With the formula editor, it is possible to calculate a new value from a maximum of 3
measured values. A wide range of mathematical and logical (Boolean) operations are available
for this purpose.
The Liquiline firmware offers you a powerful mathematics tool with the formula editor.
You are responsible for the feasibility of your formula, and therefore for the feasibility of
the result.