The methods for pressure measurement and the protocols used for data transmission are provided in this Supplement. Guidance is given for setting up the instrumentation and determining the uncertainty of the measurement. Information regarding the instrument type, design, applicable pressure range, accuracy, output, and relative cost is provided. Information on pressure-measuring devices that are not normally used in field environments is given in the Nonmandatory Appendices A (Piston Gauges), B (Manometers), and C [Low-Absolute-Pressure (Vacuum) Instruments].