Abstract: Apparatus for supporting an elongated sensor in a partition, which is defined by a pair of spaced apart parallel walls. The sensor is supported at a predetermined angle with a sensor end on one side of the partition and an output end on the other side of the partition. The support apparatus comprises an elongated container means adapted to extend through openings in the two spaced walls with open ends on either side of the partition. The container means is open at either end and is adapted to axially and radially support the sensor therein with the sensor end of the sensor extending into a region to be sensed on one side of the partition and the output end extending to the other side of the partition. A cap and seal arrangement is provided on the output end of the container to engage the elongated container and the output end of the sensor to thereby provide an air tight seal therebetween.