Divesoft He/O2 Analyzer, Руководство пользователя

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He/O
2
Analyzer
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Display modes
6.1 Calibration of the oxygen sensor
The oxygen sensor’s properties change over time and it is therefore necessary to recalibrate it.
We recommend that such calibration be performed at least once a month. Analyzer with the
older version than 2.4, the calibration is always necessary when changing altitude. Version 2.4
has a built-in barometer sensor, which corrects itself. If you require the most precise results,
calibrate the sensor before each measuring.
Calibration of the sensor is performed as either single-point or two-point or three-point.
During single-point calibration, the content of oxygen in air, which is known and constant
(20.95 %), is measured by the sensor. The calibration constant of the sensor is set so that the
instrument displays 21.0 % (after rounding).
Two-point calibration proceeds in the same manner as single-point calibration, but uses two
calibration gases – pure oxygen and air. Two-point calibration is more arduous as it requires
the use of oxygen. However, it provides more precise results during measuring.
Thee-point calibration is recommended for measuring hypoxic mixes, containing less than
approximately 15 % oxygen. In this case, the third calibration gas should be a gas with zero
oxygen content, i.e. pure helium or argon.
Calibration of the oxygen sensor is started by pressing the CAL key at any time during
the measuring.
As the first step of calibration, we must choose between single-point, two-point or three-
-point calibration using the and keys and confirm the selection using the key.
It is then necessary to choose the oxygen content in the calibration mixture.
The oxygen content is adjusted by tenths of a percent by pressing the key (to increase
the content) or the key (to decrease the content). Use the MODE key to choose whether to
make adjustments by tenths, whole units, or units of ten percentage points. Upon setting the
desired values, confirm the data using the
key.
For quickly setting typical values when setting the oxygen content it is possible to use the
CAL
key, which sets the oxygen content at 21 % in the case of the first calibration point or
100 % at the second point and 0 % at the third point.
Upon setting and confirming the calibration of gases, calibration of the sensor begins. The
current calibration point, sensor voltage in millivolts and the temperature of the gas appear
on the display.
After the temperature and voltage have stabilized (however, at least after ten seconds), the
STABLE prompt appears, which means that it is possible to confirm the performed calibration
using the
key. If the measured values change before the key is pressed, the STABLE
sign disappears and calibration proceeds until further steady values are attained. If multi-point
calibration is set up, then calibration according to the other gases proceeds similarly.