Calibration O 2 Sensor; Calibration Frequency - Pentair HAFFMANS c-DGM Instruction Manual

7.4 *Calibration O
Because the oxygen sensor only undergoes a very slight amount of wear as a result of
exposure, regular calibration is not required. It has been experimentally determined that after
1 million exposures (i.e. 1 million O
merely 5 ppb and at higher O
A light-pulse counter, integrated in the software, counts the number of exposures. On reaching
1 million exposures the warning "Calibrate or replace O
be re-calibrated or replaced. As a reminder, a warning symbol is displayed continuously on the
display.
O
2
After a successful calibration, the light-pulse counter is reset and the warning symbol
disappears.
In the following two principle methods are described to calibrate the oxygen sensor:

7.4.1 *Calibration frequency

At a rate of 500 measurements per day, 7 days per week, 52 weeks per year, the calibration
would have to be recalibrated once every five years.
A monthly check of the zero point is recommended (also by ISO procedures) and can easily be
performed by
flushing the c-DGM with a class 5 CO
-
filling the o-DGM with a zero-point liquid without O
-
(Na SO ; 2%).
2 3
The temperature of the c-DGM and sodium sulphite solution or calibration gas may only differ
by a maximum of ±1,5° C.
Attention!
If an O deviation of > 1 ppb is observed, then a zero-point calibration is recommended.
2
c-DGM/i-DGM
sensor
2
measurements) the O
2
values no deviation is detectable.
2
1. One point calibration
This method is recommended if a high accuracy for higher oxygen
concentration when measuring with the LHO-sensor or for low
oxygen concentration when measuring with the WLO-sensor is not
required.
2. Calibration with two gases
This method is recommended to ensure the specified accuracy
over the whole oxygen measuring range.
A sodium sulphite solution needs to be stored in a closed
bottle due to the consumption of O
, &&D E^ 'D 'D
deviation from the zero point is
2
sensor" appears and the sensor must
2
or N calibration gas.
2 2
, such as a sodium sulphite solution
2,
.
2
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