Gas analyzer with regulated measurement gas feed and dynamic dilution of samples

A continuously operating gas analyzer, comprising:

• a detector having an input and an output;
• a regulated measurement gas feed including a measurement gas pump (5, 21) at the detector input or detector output, a first choke (2) which is connected in a measurement gas line upstream of the detector (3), a second choke (6) which is connected in parallel with the series connection of the first choke (2) and the detector (3) as a bypass, a third choke (1) which is arranged in the measurement gas line and connected in series upstream of a junction (7) of the first choke (2) and the second choke (6), and a pressure regulator (8, 25) which maintains constant pressure at the junction (7) of the three chokes (1, 2, 6);
• a dilution gas line (12) with a control valve (13) for continuous dilution of the measurement gas with an inert gas, the dilution gas line being connected to the measurement gas line between the first choke (2) and third choke (1);
• a dilution regulator (15) connected to the output of the detector via a computer (10) which dilution regulator is operative to readjust the inert gas flow via the control valve (13) in such a way that an amplified detector output signal is maintained at a given reference value, wherein the dilution of the measurement gas flow increases as the measurement gas concentration increases;
• and
• a flow meter (14) arranged in the dilution gas line (12), the flow meter (14) having a measurement signal that is processed together with the detector signal in the computer (10) connected with the detector (3) and dilution regulator (15) to generate the analysis measurement.