EX-FLOW Ex-Proof (ATEX Zone-1 Certified) Mass Flow Meters / Controllers for gases
EX-FLOW instruments are thermal Mass Flow Meters / Controllers of rugged design and suitable for gas flow application in hazardous areas. The intrinsically safe measuring head is tested according to ATEX 95 Directive 94/9/EC and approved under EC-Type Examination Number: KEMA 01ATEX1172, protection II 2 G Ex ib IIC T4. The housing of the electronics compartment is to IP65 classification. Control valves can either be integrally or separately mounted, to measure and control gas flows (air-equivalent) from the lowest range (0,16 ... 8 mln/min) up to the highest range 220 ... 11.000 m3n/h - Mass Flow Meter and 10 ... 500 m3n/h - Mass Flow Controller).
An EX-FLOW Mass Flow Controller has a control valve with fast and smooth control characteristics. The flow meter and valve should be connected (via separate cables) to a power supply with galvanic isolation / preamplifier / readout system (located in the safe zone) which contains a controller board to complete the control loop. The control valve receives its input from the controller board and immediately responds to any deviation between the output signal from the flow sensor and the setpoint signal.
Bronkhorst High-Tech applies two sorts of coils:
Style "XB" = protection II 1 G/D Ex ia IIC T6; intrinsic safe coil; needs safety barrier.
Style "XC" = protection II 2 G/D Ex e mb II T4; moulded coil; no safety barrier required.
Power Supply / Readout Systems
To complete the EX-FLOW system, Bronkhorst High-Tech developed a PS/Readout unit, offering the following functions:
- safety barrier
- power supply with galvanic isolation
For more information: see Digital PS/Readout Systems
- ATEX approval Cat.2, Zone 1
- Pressure ratings up to 700 bar
- Rugged, weatherproof housing (IP65, dust and waterproof)
- Optional: low-ΔP versions up to 4...200 ln/min