The college textbook deals with main questions of metrology, as well as the measurement and control of physical quantities, that almost completely cover the range of values characteristic of technological processes in the oil and gas industry. The college textbook is addressed to students of metrology, instrumentation and technological specialties, graduate students and teachers. CONTENT Introduction………………………………………………………………………... 3 1. Contact and non-contact methods and devices for fluid level measurement…… 5 2. Methods and devices for gas flow rate measurement………………………….. 15 3. Contact and non-contact methods and devices for temperature measurement… 35 4. Contact and non-contact methods and devices for pressure measurement……. 58 5. Calculation of uncertainty in measurement……………………………………. 81 6. Self-evaluation section………………………………………………………… 77 7. Practical Work………………………………………………………………..... 88 References………………………………………………………………………. 101