Abstract: A light weight apparatus for sampling a gas mixture, especially a gas under pressure, in order to ascertain the extent of contamination in said mixture, including gaseous, liquid and solid contaminants. The apparatus includes in combination a filter means to capture a sample of the solid particulates and the vapor and a means to capture a representative sample of pressurized gas. A novel fitting in which two hypodermic needles are embedded is operatively connected to the pressurized gas at one of its ends and to a sampling tube at the other of its ends. A modified fitting is used to obtain a sample of the ambient atmosphere if this is desired.