| 摘要 |
PURPOSE:To prevent lower accuracy due to attachment of dust or the like and enable correction of instrumental errors by running a fluid from a front chamber to a rear chamber for seconds to several ten seconds through each reference meter of a meter box. CONSTITUTION:Numeral 1 indicates a meter box in which a front chamber 3 and a rear chamber 4 are formed with a diaphragm 2. A number of sonic nozzles a1, a2...an composing reference meters are fixed on the diaphragm from the front chamber 3 to the rear chamber 4. In operation, a valve of the sonic nozzle an, for example, is opened to run a fluid for seconds to several ten seconds from the front chamber 3 to the rear chamber 4. The amount of fluid run is calculsted while it is converted into a theoretical average flowrate of the sonic nozzle an in terms of an average temperature and an average pressure at the calculation time. The results is divided by the time from opening to closing the valve thereof to determine a reference flow rate. The flow rate thus obtained is compared with said theoretical average flow rate to correct instrumental errors. |
