The Dräger PEX 1000 establishes the connection between the Polytron SE Ex sensor head and the control unit. The sensor head is installed inside an explosive atmosphere (Ex zone) and monitors it for ignitable hydrocarbon concentrations. It transmits its readings via mV signals. The PEX 1000, which is installed outside the explosive atmosphere, transforms mV into standardised mA signals. It then transmits those signals to the control unit (for example, the Dräger REGARD 2410). If concentrations exceed a preset threshold, the control unit initiates the right countermeasures to ventilate and extract contaminated air from the area.

The PEX 1000 connects to the control unit and the Polytron SE Ex via a 3-core signal cable. The length of the cable covers a range of 500 metres. The device easily adapts to existing installations. It can be seamlessly integrated into or retrofitted to existing gas detection systems.

The PEX 1000 is very user-friendly and easy to handle. You can perform maintenance and calibration directly on the device using just two buttons and a two-digit display.

While secondary explosion protection aims to limit the hazard, primary explosion protection actively prevents the formation of hazardous explosive atmospheres. Along with the Polytron SE Ex and a control unit such as the Dräger REGARD 2410, the PEX 1000 fulfils all primary explosion protection requirements and is tested in compliance with EN 60 079-29-1 standards.

Generally, the output signal of catalytic sensors slowly changes, regardless of environmental influences. This signal drift is caused by the ageing processes of the pellistors. Another typical signal change in catalytic sensors is periodic fluctuations that occur in a day-night rhythm. These fluctuations occur because the influence of changing environmental conditions (especially temperature and humidity) can only be compensated for with limited accuracy. Starting with software version 2.5, the PEX 1000 transmitter features automatic zero-point calibration (Autozero). This can partially correct zero-point deviations due to long-term drift of the sensor and environmental influences related to the time of day, and improve the quality of the reading. The correction rate and the absolute limitation of the automatic zero-point calibration are based on the tolerances defined by EN/IEC 60079-29-1 standards. Automatic zero-point calibration is part of the EN 60079-29-1 measuring suitability test and is deactivated at the factory.