Bronkhorst EX-FLOW Mass Flow - Manual (Page 8)

BRONKHORST HIGH-TECH B.V.
1.4 Bronkhorst High-Tech B.V. flowhead
The flowhead has the following type of protection:
II 2 G Ex ib IIC T4 Gb
II 2 G = ATEX group and category
ib = intrinsic safe in zone 1
IIC = most dangerous explosiongroup with ignitionenergy of 20 µJ
for example: Acetylene and Hydrogen
T4 = surface temperature max. 135°C.
Gb = IEC equipment protection level
There is one gas which has a more dangerous temperature-class; CS
2
has temperature class T5. This gas
may not be measured with our meters.
The signal processing is done with a pre-amplifier, which transforms the measuring signal into a linearised
current signal.
For the power of the heater, a "zero" current of 15mA has been chosen.
The output current varies from 15 to 20mA.
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