The purpose of this item is to review the general techniques available for measuring fluid pressure and flow rate@ and to consider specific instruments for particular applications. The concerns of measurement criteria including uncertainty@ external influences@ and calibration are described. Based on the relative merits of different techniques@ guidance for the selection of an appropriate measurement technique is provided. The general background to pressure and flow measurement are introduced in Section 3. Three generic types of instruments for pressure measurement are covered in Section 4: hydrostatic gauges@ mechanical gauges@ and electrical transducers. Within each category@ the instruments that are commonly available are described and their principal characteristics are compared in summary tables. Techniques for measuring static and total pressure in a moving fluid@ individually and in combination@ are considered in Section 5@ and the precautions and conditions required for each are discussed. Section 6 describes methods for calibrating pressure measurement systems@ which apply to all types of measurement and instruments. Section 7 covers instruments and techniques for the measurement of flow rate. This section is organized by the common instruments used for this purpose@ and opens with tables summarizing the characteristics and application areas for each type. Finally@ Section 8 covers the calibration of flow rate instruments.