The Drager Polytron IR is an explosion proof infrared gas detector for continuous monitoring of combustible gases and vapours. With its stainless steel body and drift free optics this transmitter is built for the harshest offshore environments. Two models working with different wavelengths cover a broader range of detectable substances.

Technical innovation

The new model type 340 extends the area of applications for the Drager Polytron IR product line. The new wavelength of the Drager Polytron IR type 340 offers detection of alkanes at an even higher sensitivity. The possible monitoring of cyclohexane presents one of various new options for gas detection resulting from this innovation.

With both transmitter models Drager Polytron IR type 340 and type 334, Drager Safety defines the status quo of measurement technology for continuous monitoring of ambient air regarding combustible gases and vapours. Drager Polytron IR works based on the physical principle of infrared absorption. The innovative double compensated and nonfocussing optics effectively compensates all temperature and ageing effects.

With its many field proved components it sets the standard for all relevant measurement requirements. It is approved by certification that Drager Polytron IR can be used for SIL 2 (safety integrity level) safety functions.

Configuration

New is the configurable measuring range for the Drager Polytron IR transmitter: Type 334 offers 0 to 20 %LEL and up to 100 %LEL, alternatively 0 to 100 %v/v for methane. Type 340 is configurable from 5 to 100 %LEL. Configuration is menu guided and easy to perform, using a HART® handheld terminal or laptop.

For the easy calibration of the Drager Polytron IR, only one gas needs to be selected from an internal list, and this gas can differ from the gas to be measured. All data will be converted automatically to the substance to be monitored.

So, the intricate use of factors for cross sensitivity is no longer necessary. Thus for all Drager Polytron IR transmitters there is only one calibration gas required, independent of the monitored substance.

Stand-by mode (preventive maintenance function)

Using a preventive maintenance function – stand-by mode – the Drager Polytron IR transmitter does not immediately shutdown in case of dirty optics. Prior to providing a beam block failure signal, there will be a warning transmitted to the control unit.

The measurement continues in the background, and it will be switched back to normal operation when measuring gas concentrations of more than 15 %LEL. Alarming in a hazardous situation and with it the complete safety functionality will be maintained.

Datasheet