1, introductive

Vapour serves as 2 important the sources of energy, use extensively at technology of heating, refrigeration, production absorption make labour holding heat pledge, raise steam so production, carry it is OK to reach use efficiency managing and many energy resources. Accurate metric it is the key that improves energy level of management. As a result of steam characteristic, put in a lot of difficulty in metric respect, long-term since it is discharge measures medium long-standing issue all the time. On January 1, 2007 national level GB17167-2006 " metrological implement is deployed and administer general rule with source of can odd potential energy " carry out already formally, it is under the guidance of general rule, work up suits our country one set to produce enterprise characteristic, have scientific sex, economy, practical vapour is metric the equipment of appearance plan, it is current energy resources the urgent task that metric managing.

2, vapour flowmeter measures the problem that face

Discuss to facilitate, we list first the discharge equation of throttle unit of the following standard: