This document describes several techniques for measuring oil density, including: 1. Using an areometer on various oil fields and pipelines owned by energy companies. 2. Using a DMA 4500 densimeter in a chemical laboratory to measure density during registration operations. 3. Using digital density analyzers DA-500 and DA-640 in an analytical laboratory along a pipeline to measure density during registration operations using SIKN. The document provides details on the location, company, and identification number for each measurement technique. It also specifies that the book is available for purchase in various languages in electronic PDF format.