09/17/2003

Dräger Safety AG & Co. KGaA

Polytron SE Ex HT - a measuring head for hot environments

Polytron SE Ex HT - a measuring head for hot environments

Polytron SE Ex HT is a new gas warning instrument from Dräger Safety AG & Co. KGaA (Lübeck) that detects combustible gases and vapours in extremely hot environments (up to 150 °C). One application, for example, is monitoring gas turbines for hazardous natural gas leaks: for this purpose the gas sensors (measuring heads) must be installed as close to the gas turbines as possible - often beneath the sound insulation hood - where they are exposed to very high temperatures. If a gas leak is detected there, the gas warning system gives an alarm at an early stage and/or triggers countermeasures.
Based on its decades of experience in the area of catalytic bead sensors, Dräger Safety has developed this new sensor. Even at high ambient temperatures, it reliably detects combustible gases and vapours in the range of 0 to 100 % of the lower explosive limit (LEL). A great deal of development work was required to achieve the necessary explosion protection and high-temperature resistance of the instrument's materials.
Key features of the Polytron SE Ex HT measuring head include its broad operating temperature range of - 50 °C to + 150 °C, special poison-resistant sensor elements and robust temperature-resistant terminal box (galvanized cast housing). The instrument has been approved as "Category II 2G" for use in potentially explosive atmospheres (zones 1 and 2), meeting the tougher requirements of the ATEX Directive 94/9/EC.
Used in combination with controller systems such as Regard Ex or Polytron SE Ex, the Polytron SE Ex HT becomes a highly flexible and upgradeable gas warning system which can be combined with all other Polytron transmitters.