44
Note
– In analyzer service:
prevent probe membrane dry condition. For breaks in measurements the
probe is to be kept in water. Preferably it should be kept in the flow-through cell
filled with controllable water. To prevent water drain, hoses of inlet and outlet
nipples may be connected using a short tube;
haul the oxygen probe in the flow-through cell filled with water at ambient
air temperature above zero;
when the analyzer is brought from cold environment into a warm room,
prior to turning it on hold the analyzer at room temperature for at least 1 h to let
condensate vaporize.
2.5 Inspection of condition
The analyzer shall be recognized to be in normal working condition if it
meets the following requirements:
analyzer readings do not exceed ±3 ppb when the probe is placed in the
"zero" solution;
on calibration against atmospheric air (2.3.4) the displays shown in Fig.
2.6 and 2.7 do not come up and on calibration the readings
C
cal
, ppm are settled
with accuracy of ±1 % of the value predetermined from the formula
325
,
101
)
(
2
atm
cal
Р
t
Со
С
,
where
Со
2
(
t
), ppm is solubility of oxygen contained in air of 100 % humidity
in distilled water at temperature t,
С, normal atmospheric pressure of 101.325 kPa
according to table B.1;
Р
atm
is atmospheric pressure during calibration, kPa.
2.6 Troubleshooting
2.6.1 Typical analyzer troubles and remedies are tabulated in Table 2.1.
In the event of troubles shown in Table 2.1 it is necessary to take corrective
actions recommended in the "Remedy" column in compliance with paragraphs
below and Figures 1.1, 2.28.
