KROHNE BW 25 Ex II 1-2 G EN - Manual (Page 7)

DEVICE DESCRIPTION
2
7
BW25
www.krohne.com 03/2010 - 4000862901 MA BW25-Ex-II1/2G-AD R01 en
2.4 Flammable products
Atmospheric conditions, flammable fluids
An explosive atmosphere is defined as a mixture of air and flammable gases, vapours, mists or
dusts under atmospheric conditions with the values
T
atm
= -20...+60°C / -4...+140°F and P
atm
= 0.8...1.1 bar.
Outside of this range, no key data are available as to ignition behaviour for most mixtures. If the
application conditions do not fall within the above range, the risk of ignition in each individual
situation must be analysed on the basis of the known parameters (e.g. pressure, temperature,
process product, meter material).
2.5 Device category
The liquid level indicators are designed for Category 1/2 as per RL 94/9 EC and according to EN
60079-14 for use in Zone 0. The converters are designed for Category 2 as per RL 94/9 EC for use
in Zone 1.
2.6 Types of protection
BW25/.././M9./.. converters without electric components are supplied as type of protection
constructional safety "c".
Electrical circuits for M9. converters with limit switches or electronic signal outputs are supplied
as intrinsically safe, category "ia" or "ib" as per EN 60079-11.
The M10 converter is supplied as protection type "explosion proof".
The marking is:
The marking contains the following information:
Version BW25/.././M9./.. c
Version BW25/.././M9./../.../.. Ex ia IIC T6
Version BW25/.././M10 Ex d IIC T6
cccc constructional safety "c"
ia ia ia ia Intrinsically safe, level of protection "ia"
d dd d flameproof enclosure
IIC IIC IIC IIC Suitable for gas groups IIC, IIB and IIA
T6 T6 T6 T6 Suitable for temperature classes T6 ... T1
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