
Manual CWD 2005
Installation
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Manual CWD2005.doc
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4.1.
Shelter requirements
The calorimeter shelter is subject to special conditions. How well these conditions are
met is of extreme importance for the quality of the measurement. Room temperature
changes must be slow. If necessary, only well controlled climate systems should be
used.
If an electrical heater is used, the controller should be programmed very carefully.
Direct sunlight from a window should be avoided, since the additional radiant heat
will disturb the energy balance in the room.
4.2.
Room ventilation
A calorimeter requires approximately 30 m³/h of air. This air must be delivered from
outside the enclosure using suitable ventilation. The fresh air should not be
connected directly into the unit but should enter the room via a heater or a
roundabout route, so that the temperature of the air has time to adjust to the internal
enclosure air temperature. With some careful design and attention to a few simple
points the possibility for thermal shock can be greatly reduced or eliminated
completely.
Note:
Sections 4.1, 4.2 and parts of 4.3 are for customer guidance if a shelter
has not been purchased from the factory as part of the original order.
4.3.
Exhaust gas discharge
The small quantity of flue gas is mixed with 25 m³ of air after combustion and is
heavily diluted with an exhaust temperature around 8-10 °C (15°F) above ambient.
Flue gases must be discharged from a flue gas outlet to ensure that the thermal
balance is not disrupted. This is particularly important with small enclosures or
shelters, as air inside may become Oxygen deficient and stale if the supply of
combustion air is too small. The very small quantity of sample gas is equal to several
pilot lights on a domestic stove and poses no health hazard for most process gases
such as Natural gas etc.
With corrosive gases, it is an advantage to generate a slightly higher pressure in the
shelter (ventilator or fan), so that all flue gases are discharged from the outlet.
Corrosive air in the calorimeter enclosure will result in corrosion in the electronic
components. In some cases, it is advantageous for an enclosure or shelter to be
purged with clean dry instrument air.
All parts of exhaust system are included with the instrument. All dimensions are in
mm. Connect an exhaust tube (not supplied) as shown (1).