This is a reaffirmation of ASHRAE Standard 125-1992. This standard falls under the Standards Committee classification of Standard Method of Measurement. This standard was prepared under the auspices of the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). It may be used, in whole or in part, by an association or government agency with due credit to ASHRAE. Adherence is strictly on a voluntary basis and merely in the interests of obtaining uniform standards throughout the industry.

This standard describes tests for determining the measurement accuracy of thermal energy meters for indicating the amount of thermal energy added to, or extracted from, a liquid stream. Procedures are provided for testing meters designed for domestic hot water, heating only, cooling only, or combined heating and cooling service. Two test facility concepts are described that have proved useful for calibrating such meters.