Abstract: A device for the continuous measurement of the ammonia concentration in gases in the ppm range includes a columnar absorption vessel (1) with a hemispherical bottom (4). The bottom of the column includes an overflow (3) and an outlet (5). The gas introduction pipe (7,8) empties above the bottom (4) and below a sieve bottom (6) arranged in the column (1). A packing material (10) rests on the sieve bottom (6), which packing (10) essentially fills the absorption column (1). A cooling part (11) extends from the absorption column (1). The cooling part (11) includes a cooling zone (15) and a gas collection space (16) above it with a closable connection piece (13). A pipe (14), which may include a serrated crown on each end, runs from the gas collecting space (16) downward in a cooled manner to the packing 10. The liquid absorption agent is introduced through a lateral connection piece (18) into the gas collection space (16).