Calibration (Cont); O 2 Sensor Calibration; O 3 Sensor Calibration - Hach ORBISPHERE 410 Quick Operator's Manual

Calibration Results
A calibration screen will be displayed showing
current measurement data which is continually
refreshed.
The value "% ideal current" is a percentage of the
c u r r e n t a g a i n s t t h e i d e a l c u r r e n t f o r t h e
membrane type selected. If this percentage is not
within the accepted range, an error message is
displayed and the calibration process fails. A
warning message can be displayed when this
value is close to boundaries, but calibration can
be accepted.
The message is first displayed in the result box.
The dialog box with the error message or the
warning is displayed when the finish button is
pressed.
The value "% last calibration" shows the ratio
between current measurement and previous
sensor calibration.
The value "% variation" indicates the variation
during the last 3 measurements, which is the
stability of the measurements. A variation as low
as possible is wanted for a precise calibration
T he display sho ws t he actua l calib ra tio n
p a r a m e t e r s , a n d t h e a c t u a l r e a d i n g s
(temperature, barometer, current).
In case of calibration failure, consider replacing
the membrane.
Page 8

Calibration (cont)

O Sensor Calibration
2
The sensor is either in contact with:
•
•
In Air Calibration
This calibration procedure places the O
water-saturated air, to provide a known oxygen
reference against which to calibrate.
Dry the sensor thoroughly, before placing the
sensor storage cap under tap water. Shake off
any excess water, but leave a few drops inside
the cap. Verify that the screw-on protection cap is
in place on the sensor head. If you use a Dacron
mesh inside the protection cap, make sure it is dry
before attempting to calibrate. Then, loosely place
the storage cap back on the sensor, holding it in
place by a few turns of its collar.
Set the calibration parameters accordingly and
press calibrate.
Direct Calibration
This procedure calibrates the oxygen sensor
against a liquid sample containing a known level
of dissolved O
The instrument displays the sensitivity of the
sensor as a percentage of the sensitivity
determined when calibration was last performed.
Set the calibration parameters accordingly and
press calibrate.
O Sensor Calibration
3
The sensor is either in contact with:
•
•
Procedure is the same as for the O
case of the "In air" calibration, the sensor
m e a s u r e s O
coefficient is deduced taking into account how the
sensor behaves in O
used at the anode to measure O
measurement takes a long time to stabilize. To
facilitate the follow up after an "O
calibration, negative value can be displayed.
Air at atmospheric pressure (In Air)
O at known concentration (Direct value).
2
The gas can be dissolved or not.
flowing through the sample line.
2
Air at atmospheric pressure (In Air)
O at known concentration (Direct Value).
3
The gas can be dissolved or not.
d u r i n g c a l i b r a t i o n . T h e O
2
. As a different voltage is
2
sensor in
2
sensor. In the
2
3
and O , the O
2 3 3
in air"
3