Ineffective sample conditioning is the most common source of error in the analysis of natural gas. Recent developments in hardware now make it possible to overcome several common sources of sample conditioning problems. The hardware first separates liquid, if present, from sample gas and returns it to the pipeline. It then regulates the pressure to lower the hydrocarbon dew point. Both operations are conducted at the prevailing pressure and temperature of the pipeline to prevent gas phase distortion, which would otherwise occur. The hardware is easy to install and maintain and can be applied to sample conditioning for all types of “on line” natural gas analyzers