DEVICE DESCRIPTION
2
7
GA24
www.krohne.com
04/2015 - 4000836702 - MA G24-Ex-II2G-AD R03 en
2.4 Flammable products
Atmospheric conditions
Atmospheric conditions
Atmospheric conditions
Atmospheric conditions
An explosive atmosphere is a mixture of air and flammable gases, vapours, mists or dusts under
atmospheric conditions. The following values define it T
atm
= -20
°
C...+60
°
C /
-4
°
F...140
°
F and P
atm
= 0.8...1.1bar. Outside of this range, no key data are available as to ignition
behaviour for most mixtures.
Operating conditions
Operating conditions
Operating conditions
Operating conditions
Variable area flowmeters operate outside of atmospheric conditions, which means that
explosion protection according to Directive 94/9/EC (ATEX)
–
regardless of the zone assignment
–
is fundamentally not applicable due to the lack of key safety data for the interior of the
measuring section.
2.5 Equipment category
Variable area flowmeters are designed in accordance with EN 60079-0 and EN 60079-11 in
category II 2 G for use in zone 1. The inside of the measuring unit is also approved for zone 1.
2.6 Types of protection
The variable area flowmeter is designed with protection type intrinsic safety, protection level "ia"
as per EN 60079-11.
The marking is: II 2G Ex ia IIC T6...T1 Gb
II 2G Ex ia IIC T6...T1 Gb
II 2G Ex ia IIC T6...T1 Gb
II 2G Ex ia IIC T6...T1 Gb
CAUTION!
Operation with flammable products is only permissible if no explosive fuel/air mixture is formed
on the interior of the flowmeter under operating conditions. The user is responsible for the safe
operation of the flowmeter with regard to the temperatures and pressures of the products used.
In case of operation with flammable products the measuring units must be included in the
periodic pressure tests of the system.
INFORMATION!
Definition of zone 1 according to EN 1127-1, Appendix B:
An area in which an explosive atmosphere may occasionally occur as a result of the mixture of
flammable substances in the form of gas, steam or mist with air under normal operation.
The marking contains the following information:
The marking contains the following information:
The marking contains the following information:
The marking contains the following information:
II
IIII
II
Explosion protection Group II
2222
Device category 2
G
G
G
G
Gas explosion protection
ia
ia
ia
ia
Intrinsically safe, protection level "ia"
IIC
IIC
IIC
IIC
Suitable for gas groups IIC, IIB and IIA
T6...T1
T6...T1
T6...T1
T6...T1
Suitable for temperature classes T6 ... T1
Gb
Gb
Gb
Gb
EPL, suitable for zone 1 or zone 2
