<p>The optical analyzer (1) has housing (2) and a radiation-transparent housing element (3). A radiation source (4) is provided and a reflector (5) is assigned with two detectors. An external reflector (8) is arranged outside the housing. An absorption chamber (9) is formed from the external reflector and the radiation-permeable housing element. The external reflector has a non-reflective recess (12) of measuring beam and is arranged behind or in space of a third detector (13).</p>
