A portable sampling system for sampling gases from a flue stack and removing at least some moisture from the sampled gases, the system comprising: a sample probe that withdraws a sample of a gas, wherein the sample probe includes: a probe shaft that is dimensioned and arranged to be inserted into the flue stack, and a probe body coupled to the probe shaft, wherein the probe body includes a heater and an ammonia scrubber; an input/output system contained in a housing, wherein the input/output system includes a first vacuum pump that is arranged to provide suction to draw the sample of gas into the sample probe, and further wherein the input/output system receives and filters gas from the ambient environment to use as a purge gas; a dryer comprising a perfluorosulfonic acid membrane in the form of plural tubes, the tubes disposed within a shell in the form of tubing, wherein: (i) the dryer is fluidically coupled to and between the sample probe and the input/output system, (ii) the dryer is flexible, (iii) a portion of the dryer is covered by a heating jacket, wherein the portion is less than about 20% of a total length of the dryer, (iv) an interior of the tubes receive the sample of gas, and (v) an exterior of the tubes are exposed to the purge gas from the input/output system; and a second vacuum pump for drawing the gas from the ambient environment into the input/output system, and from the input/output system, as purge gas, to the dryer. a sample probe that withdraws a sample of a gas, wherein the sample probe includes: a probe shaft that is dimensioned and arranged to be inserted into the flue stack, and a probe body coupled to the probe shaft, wherein the probe body includes a heater and an ammonia scrubber; a probe shaft that is dimensioned and arranged to be inserted into the flue stack, and a probe body coupled to the probe shaft, wherein the probe body includes a heater and an ammonia scrubber; an input/output system contained in a housing, wherein the input/output system includes a first vacuum pump that is arranged to provide suction to draw the sample of gas into the sample probe, and further wherein the input/output system receives and filters gas from the ambient environment to use as a purge gas; a dryer comprising a perfluorosulfonic acid membrane in the form of plural tubes, the tubes disposed within a shell in the form of tubing, wherein: (i) the dryer is fluidically coupled to and between the sample probe and the input/output system, (ii) the dryer is flexible, (iii) a portion of the dryer is covered by a heating jacket, wherein the portion is less than about 20% of a total length of the dryer, (iv) an interior of the tubes receive the sample of gas, and (v) an exterior of the tubes are exposed to the purge gas from the input/output system; and (i) the dryer is fluidically coupled to and between the sample probe and the input/output system, (ii) the dryer is flexible, (iii) a portion of the dryer is covered by a heating jacket, wherein the portion is less than about 20% of a total length of the dryer, (iv) an interior of the tubes receive the sample of gas, and (v) an exterior of the tubes are exposed to the purge gas from the input/output system; and a second vacuum pump for drawing the gas from the ambient environment into the input/output system, and from the input/output system, as purge gas, to the dryer.