At home in ATEX atmospheres: LC500 series air flow controllers from EGE
Monitoring air flows has been an essential safety element in the operation of plant and machinery for many years. If this occurs in ATEX zones, the flow controllers used must meet the relevant requirements. Machine designers and plant manufacturers are making the right choice with the new LC500 series air flow sensors from EGE.
One of the traditional ways in which air flow monitors are used is for monitoring filter systems. The sensors can be used, for example, to determine the right time for a filter change. Air flow controllers are also used for monitoring ventilation systems. Airflow monitoring is straightforward in unproblematic environments such as these. However, things are very different when airflow measurement is required in atmospheres which are potentially explosive due to gas or dust.
ATEX atmospheres are a particular challenge
For these applications, only sensors which are ATEX-compliant can be used. Ideally, these can be set up and operated quickly and easily during operation in the Ex zone. Another important issue is materialisation. The housing material, or rather parts coming into contact with the medium, must also meet the strict ATEX specifications and must be able to withstand the medium. The evaluation electronics should also be ATEX-compliant. Since this is often not the case, these must be housed in a separate control cabinet.
Compliant with device category 3: suitable for Ex Zones 2 and 22
The Bachofen technology partner and sensor specialist EGE has managed to reconcile these complex requirements. The newly developed LC500 series air flow controllers measure air flows in exhaust and supply air lines in areas where Ex category 3 devices are mandatory. The evaluation electronics are integrated in the sensor. The limit value is set using a potentiometer during operation in the Ex zone. Depending on the type, a 2- or 3-colour illuminated dot signals the current flow status. This can, however, also be output via the 4…20mA or PNP switching output for further processing to a control system. When the air flow reaches the limit value, the illuminated dot colour and output signal state changes.