A Polish research team developed a new device. The intrinsically safe PXX-1multifunctional devices are designed for on-line monitoring of physical and chemical atmospheric parameters in mines and other explosion-hazardous areas. These devices are equipped with compensation elements to compensate measurement-disturbing factors such as: dust, humidity, gases and chemical substances, airflow, temperature and pressure changes. The team is looking for a partner interested in technical co-operation.

A Polish research team developed intrinsically safe PXX-1multifunctional devices for on-line monitoring of physical and chemical atmospheric parameters in mines and other explosion-hazardous areas.

The PXX-1 devices group consists of:
1. PT-1 designed to measure oxygen level, air humidity, temperature and pressure
2. PTW-1 designed to measure level of CO, temperature, pressure and level of one of the following gases: O2, SO2, H2S, NOX, H2
3. PM-1 designed to measure methane and oxygen levels as well as temperature and pressure

Electrical and metrological parameters of all aforesaid devices conform to European standards. The devices are equipped with the most modern sensors available on the market. Electronic modules of the devices are made in SMD (surface mounted device) technology. Design of all the devices is unified to achieve lower production cost, easier maintenance and service.

The devices can operate within the 7,5V ÷ 15,5V voltage range and are equipped with analogue outputs of 0,4 ÷ 2V. The calibration process of measurement converters is performed electronically using a 4-key keyboard. The design of the PXX-1 devices includes a set of elements compensating the most important measurement-disturbing factors. To reduce influence of humidity and dust a set of hydrophobic filters was implemented. The filters are constructed of porous diffusion membranes with adequately chosen parameters. They eliminate entirely transport of H2O steam to the detector and simultaneously, because of high porosity, almost do not affect the diffusion of gases. Hydrophobic and smooth surfaces of the membranes prevent settling of steam and dust molecules as well as blocking access of gasses to the measuring elements.

To eliminate the influence of gas and chemistry pollution on detector operation, multilayer chemical filters of adequate construction were used. Their task is to clean an analysed mix out of undesired components, before it reaches the measuring element.

Chemical filters together with anti-dust filters make one compact unit. Elimination of temperature and pressure changes impact on measurement indications is done by the devices software. For that purpose T and P (temperature and pressure) detectors implemented in all the devices were used. An oxygen detector, used in the PM-1 device, allows correction of measurements from the methane detector in case of oxygen level decrease below stoichiometric value.

Innovative Aspects:
Correction of indications of pellistor methane detector in situation when level of oxygen, essential for proper combustion process, decreases below stoichiometric value.

Main Advantages:
The PXX-1 devices with adequate correction elements are resistant to external measurement-disturbing factors. Because of that fact and because of their robust construction they can operate even in very hard environmental conditions. All the PXX-1 series devices are EEx ia I (Intrinsically-safe performance class - more than IP54 class) approved, which makes them ideal to operate in methane mines and other explosion-hazardous areas.

• Electronic circuits, components and equipment
• Data Processing / Data Interchange, Middleware
• Sensory/Multisensory Technology, Instrumentation related to construction technology
• Assessment of Risk
• Fire Safety Technology

• ENVIRONMENT
• INDUSTRY
• MEASUREMENTS AND STANDARDS

• Controllers
• Other measuring devices (including ifrared gas analysers, moisture analysers)
• Coal related equipment
• Other Energy
• Other Industrial Products (not elsewhere classified)

• Technical Co-operation