
pH/chlorine regulator AUTODOS 5000 - 2005-01-21
Eng_Autodos5000.doc ver 3.2 - page 21
3.1.3. Free Chlorine Calibration (ProMinent chlorine electrode 4-20mA CLE 3-mA-10ppm)
Two point calibration (zero point and gain) against a photometer measured value (ex. DPD no.1).
Gain calibration should be carried out weekly, zero point calibration is normally not needed but is possible. If the
zero point calibration is not to be performed (normal case) then ignore item 2 below (but pay attention to correct
water flow!).
1.
Enter calibration by pressing the
'CAL'
button until the
'ACTIVE'
LED lights.
2.
For zero point calibration place the electrode in chlorine free water or in the air. Wait one hour and then press
the button
'
↓
'
below display 1, zero point calibration is now complete. Before any further calibration can take
place the electrode must be allowed to monitor in the metering cell for at least 5 minutes. This is to ensure a
reliable reading for the next calibration. 1 hour is a long time to wait for
zero calibration
and a
quicker
alternative
is to remove the membrane, in that case the zero value is stabilised in one minute.
3.
Enter calibration ADJUST by pressing the
'CAL'
button until the
'ADJUST'
LED lights. The latest correct
electrode signal is now stored.
4.
Take a water sample and ascertain the correct chlorine value.
5.
Set the correct chlorine value on display 1 by means of the '
↓
' or '
↑
' buttons.
6.
Leave calibration by pressing the
'CAL'
button until the
'ADJUST'
LED is cleared.
Note. If the electrode signal differs significantly from the expected values an electrode fault will be indicated by text
display 'EL1' or 'EL2'. The AUTODOS 5000 will continue to use the calibration values from the last successful
calibration and the electrode fault will be automatically reset about one second after releasing the calibration button.
Chlorine value may be calibrated down to a lower limit of 0.05 ppm.