First published in 2003, Standard 41.10 is designed to help users select a suitable flowmeter for measuring volatile refrigerant mass flow rates and perform the test measurement.

Selecting an appropriate refrigerant mass flowmeter can be a daunting task given the wide variety of operating principles, measurement precision, and costs of commercial products. Some meters can be used for either liquids or gases, while others can be used only for liquids or only for gases. Considerable pressure losses are inherent in some approaches, but the pressure losses in some other types of meters are very small and often negligible. Useful basic information can be found in the 2005 ASHRAE Handbook—Fundamentals, Chapter 14, “Measurements and Instruments,” and in various textbooks that focus on measurement technology. Once a meter has been selected, the user may need to consult with the meter manufacturer regarding installation specifics, operations, range limits, calibration limits, and other similar performance specifics in order to obtain the
expected measurement accuracy.

This revision of the standard incorporates updated references, makes some minor text edits to improve readability, and revises Appendix B so that the flow rates are in appropriate SI units.

Units: Dual