Emerson Process Management GmbH & Co. OHG
S-2
X-STREAM XE
Short Form Manual
HASXEE-SFM-HS
05/2017
TERMS USED IN THIS INSTRUCTION MANUAL
Lower Explosion Limit (LEL)
Volume ratio of
flammable gas in air below
which an explosive gas atmosphere will not
be formed: the mixture of gas and air lacks
sufficient fuel (gas) to burn.
Upper Explosion Limit (UEL
)
Volume ratio of
flammable gas in air above
which an explosive gas atmosphere will not
be formed: the mixture of gas and air is too
rich in fuel (deficient in oxygen) to burn.
Flammable Gas(es)
Gases and gas mixtures are assigned to be
flammable if they might become ignitable
when in a mixture with air.
Explosive Gas(es)
Flammable Gases and gas mixtures in a mix
-
ture with air within the explosive limits.
Infallible Containment
This term is derived from the standards of
explosion protection especially from the re-
quirements for pressurized housings: thus an
infallible containment can be characterized
by no intended leakage out of the gas paths
enabling gas to enter the inner compartment
of the analyzer housing.
NAMUR
NAMUR is an international user association of
automation technology in process industries.
This organisation has issued experience re-
ports and working documents, called recom-
mendations (NE) and worksheets (NA).
Protection Class IP66 / NEMA 4X
Both terms are used to specify conditions for
equipment to be installed outdoor.
IP
stands for Ingress Protection, the first num
-
ber specifies protection against solid objects
(
6. = dust tight
) while the second number
specifies the degree of protection against
liquids (.
6 = heavy seas
).
NEMA
stands for National Electrical Manu-
facturers Association.
4X
specifies a degree
of protection to personnel against incidental
contact with the enclosed equipment; to pro-
vide a degree of protection against falling dirt,
rain, sleet, snow, windblown dust, splashing
water, and hose-directed water; and that will
be undamaged by the external formation of
ice on the enclosure
