The object of any sampling procedure is to obtain a representative sample of hydrocarbons from the system under investigation. Any subsequent analysis of the sample, regardless of the test, is inaccurate unless a representative sample is obtained. Due to the wide variation in flowing streams and the components in these streams, the proper sampling techniques must be employed in order for the sample to be taken, transported, stored, and finally analyzed by some type of test device. The first factor that must be covered is the person chosen to physically take the spot sample, or install and maintain the sampling device. This person is the beginning of a successful sampling program. The final outcome of the sample operation will be determined by the efforts of this first link in an unbreakable chain of operations that must be performed without variances which can and will affect the outcome of the results obtained. The philosophy of the persons involved in the sample taking will need to be sound. Their techniques must conform to the requirements of the technology and accuracy required in order to effectively take a representative sample. An inaccurate sample could cost a company untold millions of dollars in lost revenue or contribute to the improper design of plants, and in addition, cause incorrect plant or pipeline balances. The therm billing that is being used throughout the industry requires that all functions of gas measurement, including sampling, be done with considerable care and utilizing specific techniques.