Category
ATEX Portable Gas Flowmeter
Spot-check gas and air flow in hazardous areas with Höntzsch handheld flowtherm portable flowmeters.
An ATEX portable gas flowmeter is a handheld instrument certified for spot-checking gas flow in areas classified for explosive atmospheres. The Höntzsch flowtherm Ex is rated II 2G Ex ib IIC T4 for Zone 1 and Zone 2 gas areas, and the multi-sensor flowtherm NT.2 is also available in an ATEX version. For non-hazardous sites, see Portable Gas Flow Meters.
2 Products · ATEX Approved Portable Gas Flowmeter
Selection guide
ATEX Portable Gas Flowmeter Guide
How a portable gas flowmeter works in a hazardous area
A probe is inserted into the duct or pipe through an access point and reads velocity or flow, which the handheld unit displays and logs. In a hazardous area, both the evaluation unit and the probe must carry certification for the zone, not just the unit alone. Intrinsic safety, marked Ex ib, limits the electrical energy in the circuit so a fault can't generate enough heat or spark to ignite the surrounding gas.
How to choose an ATEX portable flowmeter
- Zone and gas group: confirm the zone classification (0, 1 or 2) and the gas group at the measuring point. The flowtherm Ex is rated II 2G Ex ib IIC T4, suitable for Zone 1 and Zone 2.
- Sensor type: the flowtherm Ex works with a single thermal or vane wheel probe, while the flowtherm NT.2 is a multi-sensor unit with data logging, for comparing readings across several points.
- Probe certification: every probe used with the meter needs certification matching the same zone. Tell us your access points and probe lengths and we'll confirm compatible certified probes.
- Use in safe areas too: an Ex-certified flowtherm can also be used in non-hazardous areas, which suits contractors covering mixed sites with one instrument.
For continuous, fixed-point flow readings, see flameproof airflow and velocity transmitters.
FAQ
Common questions
What does II 2G Ex ib IIC T4 mean on the flowtherm Ex?
It's the ATEX marking. Category 2 for gas means the instrument suits Zone 1 and Zone 2 areas, Ex ib is the intrinsic safety protection method, IIC is the gas group (which includes hydrogen and acetylene), and T4 is the temperature class, a maximum surface temperature of 135 °C.
Do the flow probes need separate ATEX certification?
Yes. Everything used in the hazardous area, including the probe, must be certified for that zone, not just the handheld evaluation unit. Share your zone classification and access points and we'll confirm probes that are certified to match the flowtherm Ex.
Can I use the flowtherm Ex for spot checks in several plant areas?
Yes, that's its main use: a portable unit for periodic spot checks rather than a fixed installation. An Ex-certified instrument can also be used in non-hazardous areas, so one flowtherm Ex can cover both classified and safe zones on the same site.
What is the flowtherm NT.2 used for?
It's a multi-sensor portable evaluation unit with data logging, suited to comparing flow readings from several probes or points during a survey. An ATEX version is available for use in hazardous gas areas, alongside the single-sensor flowtherm Ex.
Is a portable flowmeter enough, or do I need a fixed transmitter?
A portable meter like the flowtherm Ex suits spot checks and commissioning surveys. For continuous monitoring of a duct or fan, such as ID fan velocity in a dust collector, a fixed flameproof airflow transmitter gives a permanent 4 to 20 mA output instead.
Need help?
Can't find what you need?
Our team helps you select the right atex approved portable gas flowmeter products for your application. Request a quote or discuss your requirements.
Expert product guidance
Tailored selection of atex approved portable gas flowmeter instruments
Custom solutions
Instruments customized for your specific industrial setup
Trusted global brands
Full warranty and official documentation support