The heated self-regulating sample lines of the PSG Ex2 Extruded SR series are used for the continuous analysis of extractive gases. They are primarily used to transport the wet sample gas stream from the sample point to the analyzer house. The holding temperature of the line must therefore be higher than the water vapor or acid dew point of the sample gas. This prevents uncontrolled condensation of the water vapor on the way to the analyzer and thus the washing out of the gas components in the condensate. Measurement failure due to a freezing line at ambient temperatures below 0°C is also prevented.
The rugged lines with a thick-walled, flame retardant TPU or extruded PVC outer jacket are extremely well equipped with a high-quality, self-regulating Raychem® heating cable. The insulation is made of thermal fleece or fiberglass. The patented Ex2 technology is used to prevent electrostatic charges. Depending on the heating cable used, holding temperatures of up to 150°C at -20°C can be achieved. Solutions down to -52°C are also possible. Up to 12 PTFE, PFA, stainless steel or special alloy tubes as internal line and also interchangeable internal tubes are available.
Due to the self-regulating heating cable for operation, an additional temperature controller is not required. The heating cable consists of two parallel supply conductors connected to an electrically conductive polymer plastic. During operation, the conductivity of the plastic decreases with increasing temperature due to molecular expansion until the specific maximum temperature of the heating cable is reached. When the temperature of the heating cable now drops, the process reverses.