In the process industry, a single question decides the scope of application: is the area classified as an Ex zone or not?
The reason for the exclusion lies in the design. An inspection robot contains lithium batteries in the kilowatt-hour range, electric drives, laser scanners, charging contacts and radio modules – each of them a potential ignition source. Retrofitting is practically ruled out; explosion protection is a design decision, not an equipment option. The ingress protection rating IP67, which many data sheets state prominently, concerns dust and water, not explosion protection.
This does not exclude the industry, but it narrows it down.
What lies outside the zones
The areas outside the zone classification can be used – and in many works that is more than initially expected:
- pipe bridges and routes outside the release radii
- ancillary installations and energy centres
- cooling water circuits and cooling towers
- storage areas for non-flammable substances
- peripheral areas of tank farms
- works roads and loading areas
- workshops
Within these areas, the inspection tasks are productive: visual inspection of flange connections and fittings for leaks, thermal capture of pumps and motors, detection of incipient bearing damage via structure-borne sound or noise anomalies, reading of fill levels and pressure gauges, checking of collection pans and drainage points.
In addition, there is a technique that is often overlooked: capture from a distance. Many inspection tasks can be carried out with sufficient optical zoom from the edge of a zone without the device entering it.
Gas detection and zone approval
A word on gas detection, because this point regularly leads to misunderstandings: a robot can be equipped with multi-gas sensors and measure concentrations of carbon monoxide, hydrogen sulphide, oxygen or flammable gases. The ability to detect gas does not, however, entitle it to operate in an Ex zone. The two are often confused – in manufacturers' documents too.
The only robust wording is gas detection in non-hazardous areas.
Procedure
Anyone preparing a procurement should therefore start early with the occupational safety specialist and the explosion protection document, not with the product comparison.
The complete system – zone classification, equipment categories, gas groups, temperature classes and the procedure for determining the boundaries – is set out in Explosion protection and mobile robotics.
Sources
- Directive 2014/34/EU on equipment and protective systems intended for use in potentially explosive atmospheres European Union accessed 15 August 2026
- Gefahrstoffverordnung Bundesministerium der Justiz accessed 15 August 2026
Change log (1)
- 5 October 2026 Initial publication First publication of the English version.