钟罩式气体流量标准装置: Measured Pipe:DN15、DN25、DN40、DN50 Flow Range:(0.5~360)m3/h Accuracy:0.5 临界流文丘里喷嘴法气体流量标准装置: Measured Pipe:DN50、DN80、DN100、DN150 Flow Range:(0.5~1050)m3/h Accuracy:0.32%