Smartphones and mobile computers in hazardous areas

In the production of, for example, varnishes, paints, oils or pharmaceutical products, explosion protection is particularly important due to explosive gases or dusts and is protected by appropriate measures. Even in these dangerous areas, working with MDE/WLAN devices is possible and useful. These devices in particular have a particularly protected and robust housing. Permanently monitoring equipment and systems is the central key to greater safety, efficiency and productivity in potentially explosive working environments. Nowadays, 1D/2D barcodes and RFID transponders are increasingly being used to identify and track components and containers.

The Ex area has special requirements for the devices used

The MDE devices find their place in many industries such as industry, warehouse, trade and also in the transport sector and healthcare. With the use of mobile data collection devices Information can be recorded, stored, further processed and accessed regardless of location. The workflows can therefore be optimize and make it more efficient so that the company's success increases and resources are conserved. Explosion protection plays a particularly important role in hazardous areas. Hazardous substances are not only produced, they also have to be transported and stored. The mobile devices are continuously used in the individual stations to document the individual steps and make processes comprehensible. According to the guidelines, the mobile devices must be designed specifically for the danger area - conventional devices are out of the question. The devices used in hazardous areas must meet particularly high safety requirements to protect the storage location and the employees. In addition to mobile data collection devices, these requirements can also barcode scanner, mobile computers and Forklift terminals fulfill.

How can an explosion occur?

For an explosion to occur, three factors must be present. On the one hand, there must be fuel available, as well as oxygen and an ignition source. An ignition source can arise from sparks, overheating or a short circuit. The devices used in hazardous areas are so robust that no sparks can escape. This simultaneously prevents gases or dust particles from igniting and causing an explosion.

ATEX guidelines

Since 2003, safety standards have been legally defined by the ATEX Directive 2014/34/EU. The abbreviation ATEX stands for “atmosphères explosibles” – translated, this means explosive environments. The ATEX guidelines cover many aspects such as explosion groups, ignition sources, protective measures, temperature classes, device groups and much more. These aspects of EX areas require special ATEX approval to protect employees. Manufacturers are therefore obliged to observe the requirements for their explosion-proof products and to provide evidence of their fulfillment.

ATEX divides the level of explosion risk into specific zones. In Zone 0, employees are constantly confronted with the formation of explosive gases. In Zone 1 there may still be a risk of explosion during normal operation. Zone 2 means that, as expected, explosive gases are not to be expected here or that explosive gases only occur briefly or rarely. Combustible dust items are also divided into similar zones - here there are zones 20 to 22. Zone 20 contains combustible dusts in the atmosphere at any time or often to long-term, zone 21 only occasionally, and zone 22 usually only for a short time or never. Device manufacturers indicate the respective zones for which their devices are suitable. If these represent an ignition source, a risk assessment must be carried out by the manufacturer.

Accordingly, the devices are divided into two groups and five different device categories, which define the device requirements in more detail:

Gruppe 1

Group 1 includes the devices that are used, for example, in mining, which means there is a possible risk of dust development. A distinction is made between two categories – M1 and M2. Devices that fall under these categories cannot be assigned to a specific zone. The M1 category is defined by a very high level of safety that allows the use of devices to continue working without any problems thanks to integrated protective measures, especially when explosive substances are in the atmosphere. The devices, which are classified in category M2, switch off automatically in potentially explosive environments.

Gruppe 2

Devices for all other hazardous areas are classified in the second group - again divided into three categories. Category 1 ensures a very high level of safety, Category 2 represents a high level of safety and Category 3 represents a normal level of safety under conventional operating conditions.

In addition to the important device specifications, the special requirements of the WLAN network and the radio transmission of the devices are also crucial. Of particular note here are explosion-proof hardware components and the establishment of safe and stable wireless data transmission paths. According to the ATEX guidelines, radio devices represent a possible source of ignition due to the electromagnetic waves. Of course, this also includes all conventional smartphones and mobile computers and barcode scanners for mobile data capture.