A sample is extracted via the thermostatically-controlled sample gas probe. The dust concentration may be up to 2 g/m?, the sample gas temperature up to 600 °C. The gas is transported to the analysis cabinet via a heated sample gas line. The heating prevents condensate. The gas cooler cools and dries the sample in the analysis cabinet. Condensate is drained. The level in the condensate trap is monitored. For safety purposes, a coalescence filter can be provided in addition to the fine filter and moisture filter which are always present. The sample gas is analyzed by analyzers such as the ULTRAMAT 23, OXYMAT 6 and LDS 6. The ULTRAMAT 23 operates on the basis of molecular-specific absorption of infrared radiation or with an electrochemical oxygen measuring cell. The OXYMAT 6 is an analyzer for paramagnetic oxygen measurements. The in-situ LDS 6 laser diode spectrometer operates according to the molecular-specific absorption of near-IR radiation. The delivery may also include an NO₂/NO converter which permits measurement of total nitrogen oxides. In order to qualify the set for low or high temperature ranges (-5, +45 °C), it is possible to use a cabinet heater or air-conditioning unit. Power supply versions are available for 115, 230 or 400 V AC. Electronic consumers can be provided with single-pole or double-pole fusing. The components of the sample preparation system and the analyzers are connected to LOGO modules via a binary signal, and transmit maintenance requirements. The analog signals can be processed either singly or twice. Electrical isolation is additionally possible for the double processing.