YSI IQ SensorNet FDO Sensor - Manual (Page 22)

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Measuring / Operation FDO
®
70x IQ ...
4.2.3 User calibration
Principle The user calibration can either be done in water vapor-saturated
air or in air-saturated water (see C
HECK OR CALIBRATION MEDIUM on
page 4-1). With the calibration procedure, the relative slope of the sen-
sor is determined. The calibration is evaluated based on the relative
slope and the intensity (successful <-> unsuccessful).
The result of the user calibration is stored in the calibration record and
calibration history respectively and can be viewed afterwards (see
respective IQ
S
ENSOR
N
ET system operating manual).
Steps Generally, a user calibration on the IQ
S
ENSOR
N
ET is carried out as fol-
lows. System specific details are given in the respective IQ
S
ENSOR
N
ET
system operating manual.
We want to point out that the factory calibration of the mem-
brane is highly precise due to the IQMC technology. If you
still want to carry out a user calibration, influences due to
environmental conditions have to be taken into account.
1 Switch to the measured value display with <M> and select the
FDO
®
70x IQ ... sensor.
2 Press <C>.
The next step switches on the maintenance condition for the
sensor. A corresponding message appears on the display.
3 Confirm the note with <OK>.
The maintenance condition is active.
4 Select the CALIBRATION procedure and press <OK>.
5 Put the sensor into the calibration position (water vapor-satu-
rated air or air-saturated water - see section 4.2.1).
6 Press <OK>.
The sensor determines the calibration data. The display
switches to the measured value display. The CAL indicator
flashes instead of the main measured value. At the same time,
the momentary relative slope flashes as the secondary mea-
sured value. The process ends automatically as soon as the
measured values meet the criterion for the stability control.
With a great temperature difference between the sensor and
the environment this may take a while. Subsequently, the main
measured value and temperature are displayed.
7 If the user calibration was successful, bring the sensor into the
measuring position again.
8 Wait for the measured value to be largely stable (temperature
adjustment).
9 Switch off the maintenance condition.