measuring conditions of para O2
The paramagnetic oxygen analyser is a unit for attachment mounting. By means of clamping rails which are to be ordered separately, flush-type control-panel mounting is also possible. The unit is dust-proof and splash-proof.
The place of installation for the analyser must stable and possibly vibration-free, dry and clean.
The time behaviour of the measuring equipment is improved the unit is mounted near the gas sampling position. Because the unit is not explosion-proof the place of installation must be free of explosible gases and gas mixtures.
If the gas to be measured is combustible or particularly aggressive, it must be checked that and under which conditions the analyser can be used. If the gas to measured is toxic, it must be taken care that the gas escaping from the unit or the measuring equipment is led off without danger.
Moreover, the operator of the unit has to carry out routine checking for tightness of the measuring equipment or to provide for sufficient aeration of the room where the unit is installed. As for further environmental conditions, confer to Section 10.
If the analyser is accommodated in a heated outdoor cabinet or control room in the open air, then it must be paid attention that when in operation, the analyser is not exposed to lower temperatures than + 5 °C upon failure of the heating.
The analyser must, be filled with dry and clean measuring gas.
The following requirements are placed on the measuring gas:
Flow rate: 10 to 60 l/ h
When the gas freely escapes from the unit, the pressure of the measuring gas corresponds to atmospheric pressure. Variations of the atmospheric pressure cause an extra error of the unit which especially in case of suppression of the starting value of the measuring range, or, elevated accuracy requirements must be balanced using the discharge control 17 (Figure 3). When leading the measured gas into pressurized waste-gas lines, errors arise.
In order to reach a low water vapour concentration, the measured gas must be cooled. Especially in case of suppressed measuring ranges with a small measuring span, a narrow variation width of the residual humidity must be obtained by drying (15; Figure 3).
Limitation by a fine filter of pore size <=1 µm.