Calibration Chlorine (Cl) / Bromine (Br)); Calibration Procedure; Calibration Errors - Bayrol PoolManager Chlorine User Manual

13.3

Calibration chlorine (Cl) / bromine (Br))

INFO
PoolManager PRO only
®
Calibration for free chlorine / bromine measurement is performed as 1-
point calibration. The pool water's DPD measured value is entered as
reference value. It can be measured using a photometer. Alternatively,
a simple colour test can be used. However, this is not recommended
due to the limited precision.
IMPORTANT NOTICE!
Calibration near to setpoint
For reliable and precise calibration of chlorine / bromine
measurement, this has to be performed as close to the
desired setpoint as possible.
 First bring the chlorine / bromine concentration in
the pool to the desired level (=setpoint) via manual
dosing or manual addition.
 Check the value via DPD measurement
 Do not perform calibration until the value in the
pool is close to the desired setpoint (recommended
tolerance approx. setpoint ±10%)
IMPORTANT NOTICE!
Calibration for bromine
Bromine concentration and chlorine concentration can
be calculated using DPD measurement. However, the
same colour on the DPD sample means different
values for chlorine and bromine.
 If your photometer / colour tester explicitly supports
bromine measurement, then you can use the
bromine value read directly.
 If your photometer / colour tester only supports
chlorine measurement, then you have to multiply
the chlorine value by 2.2 in order to obtain the
correct bromine value (e.g. DPD measurement for
chlorine displays 1.0 mg/l
INFO
Internal 2-point calibration
Even if you only have to enter one calibration point,
Analyt internally performs a precise 2-point calibration.
The second calibration point used is the zero point from
the potentiostatic measurement, which is always nearly
constant.
13.3.1

Calibration procedure

Chlorine / bromine calibration can be found in the following menu:
Calibration Cl (Br)
Calibration is carried out as follows:

Select Calibration Cl

Calibration is a menu sequence, i.e. it goes through a series of
menus step-by-step.
13.3.1.1 Calibration Data
The following parameters are displayed in the Calibration menu:
Calibration value
Enter the measured DPD value as the calibration value (calibrate
close to setpoint!).
bromine 2.2 mg/l).

Current value
This is the current measured value calculated using the parameters
from the last calibration, which are still valid. This value may deviate
from the actual value. It is only displayed to give you a certain level of
orientation throughout calibration.
Using the measured value, you can see whether measurement is
sufficiently stable for reliable calibration.
13.3.1.2 Calibration results
At the end of calibration, the calibration parameters calculated are
displayed:
Offset
Offset is the zero point shift calculated from calibration. It is indicated
in [mg/l].
Current value
The chlorine / bromine measured value is now calculated using the
parameters from the current calibration. The measured value
displayed should therefore be consistent with the calibration value
entered.
13.3.1.3 Step by step
Calibration to the measured DPD value
1. Take a water sample from the measurement chamber and
calculate the chlorine / bromine value using a photometer
(DPD1 method).
2. In the menu, select the function Calibration Cl
3. Enter the pool water's DPD value calculated as the calibration
value
4. If the measured value displayed and the Current Signal are
stable and are no longer changing in a relevant manner, then
confirm calibration by pressing Next.
5. Check the calibration results displayed and close calibration by
pressing Ready.
13.3.2

Calibration errors

During calibration, various plausibility criteria are checked. If one of the
criteria is not met, then a corresponding error message appears and
calibration is not executed.
The following criteria have to be met for successful calibration:

Calibration must be performed for a calibration value (DPD value)
of at least 0.20 mg/l.

The offset calculated (zero point shift) has to be in the range of
±1.00 mg/l. The offset is generally close to 0 for flawless
electrodes.

The slope calculated has to be in the range of 1 µA/mg/l – 250
µA/mg/l. For flawless electrodes, slope is generally in the range of
5 µA/mg/l – 20 µA/mg/l.
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