A gas analyzer is disclosed herein. The gas analyzer includes a light source for transmitting a radiation and a sampling chamber having a first opening for receiving a gas sample, a second opening for removing the gas sample, at least one optical window towards the radiation allowing the radiation to traverse the gas sample and also having a first wall and a second wall opposite to the first wall, the first wall and second wall edging the sampling chamber to guide the gas sample from the first opening to the second opening. The gas analyzer also includes at least one detector for receiving the radiation after traversing the gas sample. The first wall and the second wall of the sampling chamber is curved and at a predetermined distance from each other, an overall shape of the second wall being mostly similar to the first wall.