第一节是对证明主题的一般介绍。第4章中的要求基于API MPMS第11.1章中涵盖的原油和产品的惯例。校准仪和流量计的不确定度应适用于被测流体，并应得到相关方的同意。

Section 1 is a general introduction to the subject of proving. The requirements in Chapter 4 are based on customary practices that evolved for crude oils and products covered by API MPMS Ch. 11.1. The prover and meter uncertainties should be appropriate for the measured fluids and should be agreeable to the parties involved.