YSI IQ S ENSOR N ET VARiON Plus 700 IQ - Manual (Page 38)

Matrix adjustment, check and calibration VARiON
®Plus
700 IQ
4 - 8 ba76000e01 01/2012
4.3 Check and calibration in standard solutions
4.3.1 General information on checking and calibrating
In addition to the comparison measurement or matrix adjustment under
real measurement conditions, it is possible to check the function of the
entire sensor in standard solutions. If necessary, you can also take
over to the sensor the slope and potential level of the individual
combination electrodes via an exact calibration in standard solutions.
The slope will be retained with a future matrix adjustment if it is carried
out without zeroing the electrode.
Caution
The long term stable VARiON
®Plus
electrodes are calibration-free
with the recommended application. A check in standard solutions
is only of significance if all basic conditions (cleanness,
conditioning etc.) are strictly kept. Calibration can cause major
measurement errors if the basic conditions are not sufficiently
kept. After calibrating, a matrix adjustment is normally required
additionally
(always with the recommended application). Standard solutions
do not represent any real test sample!
When does a check or
calibration make sense?
A check or calibration can be useful in the following special cases:
 If the measured values do not appear to be correct even after a
careful matrix adjustment and if you suspect the electrode slopes to
have changed
 If a new application is to be started, the sample composition of which
considerably deviates from that of the recommended application
(see section 1.3 R
ECOMMENDED FIELDS OF APPLICATION )
 Routinely within the framework of the company quality assurance.