34
EasyLine EL3000 Series Commissioning Instructions
Housing Purge
Housing Design
Remark: Housing purge in the Fidas24 is described in a separate section,
see below.
Housing Purge is only possible with the wall-mount housing (EL3040
model). The purging gas connectors (1/8-NPT female thread) are factory-
installed based on orders.
When does a housing purge become necessary?
Housing purge becomes necessary when the sample gas contains
flammable (see page 38), corrosive or toxic components.
Purge Gas
The following is to be used as purge gas:
Nitrogen for measuring flammable gases and
nitrogen or instrument air for measuring corrosive or toxic gases
(Quality of instrument air in conformity with ISO 8573-1 Category 3,
i.e. particle size max. 40 µm, oil content max. 1 mg/m
3
, dew point
max. +3 °C).
NOTE
For Uras26, the purging gas must not contain any constituents of the
sample components! Sample component constituents in the purging gas
can falsify the measurement result.
ATTENTION
Leaks may cause the purging gas to escape from the housing. When
applying nitrogen as purge gas, appropriate precautionary measures
must be taken against asphyxiation!
The purge gas flow must always be restricted upstream of the purge
gas inlet! If the purge gas flow is not restricted until after the purge gas
outlet, the full pressure of the purge gas is exerted on the seals. This
can destroy the operator panel keypad!
Initial Purging for Start-up
Purging of the gas feed path:
Purge gas flow max. 100 l/h,
duration approx. 20 s
Purging of the wall-mount housing: Purge gas flow max. 200 l/h,
duration approx. 1 h
If the purge gas flow is lower than specified, the duration of the purging
must be extended accordingly.
