KROHNE OPTISENS PAS 2000 FR - Manuel (Page 25)

PROGRAMMATION
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OPTISENS PAS 2000
www.krohne.com 02/2010 - MA PAS 2000 R02 fr
5.3 Etalonnage
La sonde est fournie préétalonnée mais comme toutes les électrodes vieillissent, il est
nécessaire d'étalonner la sonde avec son électrode à la mise en service afin d'assurer une
mesure correcte. L'électrode se dégrade avec le temps et l'étalonnage doit être répété
régulièrement selon un planning de maintenance.
L'intervalle de temps entre les étalonnages varie en fonction de l'application, généralement
entre une et dix semaines. Il est important que la sonde ait été enclenchée 30 minutes environ
avant l'étalonnage pour qu'elle puisse se stabiliser.
5.3.1 Calibrating pH
For a pH calibration there are two alternatives: smart or manual. Irrespective of the type of
calibration you chose, you need two pH buffers which both have a common, known temperature.
For a smart calibration you need two different buffer solutions with pH 4.00, 7.00, or 10.00. For a
manual calibration, two different buffer solutions can be used irrespective of the buffer value.
Remove the sensor and, if necessary the electrode as well, but make sure that the electrode is
still connected to the signal amplifier. Make sure that you have at least 2 standard buffers
available with pH 4.00, 7.00 or 10.00 of a known temperature (it is best to pour the buffers into
plastic cups). Now do the steps that follow:
• Enter the sensor menu. The output is frozen when the menu is opened.
• Open the "Calibrate" menu, select "Calibrate", then "Smart" or "Manual" and press ^.
• A window pops up and asks for the buffer temperature. Enter the temperature and press ^.
• MAC 080 will say "Put the electrode in buffer 1". Spray the electrode using clean water, then
immerse it in the first buffer, and press ^.
• The text will say "Waiting for stable signal xxx,x mV" (xxx,x is the millivolt signal from the
electrode). By pressing ^ you can select to abort the calibration or to accept the value shown.
• If smart calibration is used and MAC 080 recognizes the buffer, MAC 080 will suggest a pH
value showing the text "Accept smart calibration pH X.X". You can choose to accept the value
or to change it manually.
• If manual calibration is used MAC 080 will always ask for the value of the buffer, enter the
value and press ^.
• MAC 080 will now tell you "Put the electrode in buffer 2". Spray the electrode using clean
water, then immerse it in the second buffer, and press ^.
• The text will say "Waiting for stable signal xxx,x mV" (xxx,x is the millivolt signal from the
electrode). By pressing ^ you can select to abort the calibration or to accept the value shown.
• If smart calibration is used and MAC 080 recognizes the buffer, MAC 080 will suggest a pH
value showing the text "Accept smart calibration pH X.X". You can choose to accept the value
or to change it manually.
• If manual calibration is used MAC 080 will always ask for the value of the buffer, enter the
value and press ^.
• The second buffer is not accepted if it is less than 1 pH from buffer 1, if so the second
calibration will be repeated.
• When the calibration is finished the slope is shown in the display ("Slope XX%"). This gives an
indication of the shape of the electrode. A good electrode has a slope between 93 and 102%.
• Press ^ to finish the calibration.
.book Page 25 Friday, February 12, 2010 11:52 AM