Emec Centurio POOL, Operating Manual

Page: 9 / 48

9
“Centurio PRO” standard settings.
Standard settings are: Probes calibration and operating modes (bleed - inhibitor - biocide). To calibrate each channel
select it within main menu. Channels availability is based on modules configuration. The controller will automatically add
the proper channel when a new module is installed and detected.
Conductivity calibration menu.
This menu includes probe choice, conductivity calibration , temperature compensation and manual or automatic temperature
compensation. Conductivity calibration procedure involves a zero calibration (First Point) and a 2nd calibration point (Second
Point) that requires a buffer solution with value near working range. Furthermore Temperature and Automatic Compensation
must be set. Note: This procedure assumes that CONTROLLER is correctly installed and configured, connected
to a working probe. Calibrate using plant’s temperature otherwise unattended results might occur. If something
wrong occurs use RECOVERY CALIBRATION to restore to previous calibration.
First Point & Second Point.
During this procedure probe must be dry and clean and not installed in plant. Tap on “First Point” (zero) and confirm it.
Tap on “Second point”, dip probe’s head into buffer solution and wait until reading value is stable, enter buffer solution
value and confirm it.
Temperature Compensation (if available)
Conductivity measurements are temperature dependent. The degree to which temperature affects conductivity varies
from solution to solution and can be calculated using the following formula: C25 = C / {1+[a/100(t-25)]} where: C25 =
slution conductivity at 25°C, C = conductivity at operating temperature, a = temperature coefficient of solution %/°C.
Probe read value
(uS or ppm)
Alpha
(a)
Temperature
(°C / °F)
Displayed Value
(us or ppm)
5227 1.2 35°C / 95°F 4934
4524 3.5 27°C / 80.6°F 4228
3924 2.1 40°C / 104°F 2984
Samples alphas (a) are listed in the table above. To determine that “a” of other solutions, simply measure conductivity at
a range of temperatures and graphic the change in conductivity versus the change in temperature. “Centurio PRO” has
either fixed or adjustable automatic temperature compensation referenced to a standard temperature of 25°C.
Otherwise choose automatic temperature compensation and set % Alpha value.