Measuring arrangements and methods for the detection of trace gases in a sample gas

A measuring arrangement for detecting trace gases in a sample gas, the measuring arrangement comprising:

• at least one narrow-band excitation light source for emitting excitation light;
• a first chamber with an inlet for the sample gas and an outlet, wherein the excitation light is emitted into the first chamber;
• a second chamber with an inlet, wherein it is separated gas-tight from the first chamber, wherein the excitation light is emitted into the second chamber;
• a scrubber, wherein the sample gas is divided after a gas inlet, wherein a part of the sample gas is directed to the inlet of the first chamber and the other part of the sample gas is directed to the scrubber,
• wherein the scrubber removes trace gases from the sample gas and background gas remains,
• wherein the background gas is directed to the inlet of the second chamber;
• at least one narrow-band measuring light source for emitting measuring light, wherein the at least one measuring light source is arranged such that the measuring light hits the excitation light in the first chamber and the excitation light in the second chamber;
• a detector unit which is in optical contact with the first and second chambers and detects the measurement light in the first chamber and the measurement light in the second chamber respectively and converts it into a first and a second electrical signal;
• and
• a data processing unit which calculates an amount of trace gases in the sample gas from the first and second electrical signals.

A method for detecting trace gases in a sample gas, comprising the steps of:

• emitting excitation light into a first and second chamber, wherein the second chamber is separated gas-tight from the first chamber;
• directing sample gas into the first chamber;
• directing the sample gas from the first chamber to a scrubber, wherein the scrubber removes trace gases from the sample gas and background gas remains;
• directing the background gas into the second chamber;
• emitting measurement light into the first and second chambers;
• detecting measurement light from the first and second chamber;
• and
• determining an amount of trace gases using the detected measurement light.

A method for detecting trace gases in a sample gas, comprising the steps of:

• emitting excitation light into a first and second chamber, wherein the second chamber is separated gas-tight from the first chamber;
• directing sample gas into the first chamber;
• directing the sample gas to a scrubber, wherein the scrubber removes trace gases from the sample gas and background gas remains;
• directing the background gas into the second chamber;
• emitting measurement light into the first and second chambers;
• detecting measurement light from the first and second chamber;
• and
• determining the amount of trace gases using the detected measurement light.